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Work and Energy.doc
Physics, Mr. Kent
Daily Worksheet: Work
Name: ________________________________
1. Awhile ago we saw Impulse: ____________ exerted over ____________ (_________)
2. Today we have a very similar, new quantity: _________________
Work:is the
____________
overperformed
____________.
Formula:
____________________
3. What
magnitude ofexerted
the work
in the above
diagram?
______________
3. A gnome exerts a force of 125 N to move a block 75 m. How much work did the
gnome perform on the block? _______________________
4. The SI-Unit for work could be called the ____________________ (_______) but work
is another of those quantities with a special name: the ______________ (______)
5. Joyce exerted 30 N to push a book along a desktop for 1.4 m. How much work did she
do? _________________
6. Joyce did 100 J of work pushing a book 2 meters across a desktop. How force did she
exert? _________________
7. By exerting a force of 50 N Joyce did 450 J of work on a book. How far did she move
the book? ________________
8. ____________ and ___________ are obviously very different. However, they have
very similar __________________. Weight: _______ Work: _______
9. A 900 kg block is pushed for 60 m with a force of 125 N.
w = ______________ W = ________________
10.With upward work, the force is the _______________ of the object _______________.
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Work and Energy.doc
11.Ralph lifts a 10 kg block from the floor to a shelf 0.25m m above the floor. What
Force did he exert? ____________ How much work did he perform? ____________
12.Use the following diagram to complete the table below the diagram:
Force
Distance
Work
A to B
B to C
C to D
Total Work
13.In lifting a box from the floor to a shelf 1.8 m above the floor Frank performs 317.5 J
of work. Weight of the box? _______________. Mass of the box? ______________.
What object performed the work? ___________________
14.When we work with Work, we have to be a little careful with our wording.
In this picture:
Work is performed by: ____________________
Work is performed on: ____________________
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Work and Energy.doc
15.Bud exerts 125 N to push a 90 kg block 75 m East. Then he turns around and exerts a force
of 60N to push the same block 50 m West.
a. Work performed to the East =
b. Work performed to the West =
c. Work performed by Bud =
d. Net work performed on the block =
____________
____________
____________
____________
16.Lisa exerts 175 N of force to pull a cart 45 m South. Then she turns around and pushes the
same car 70 m North with a force of 120 N.
a. Work performed by Lisa South =
____________
b. Work performed by Lisa North =
____________
c. Total Work performed by Lisa =
____________
d. Net Work performed on the cart =
____________
17.Jasmine pushes East on a block with a force of 75 N. Nick pushes West on the same block
with a force of 40 N. The block moves East 15 meters.
Force
Distance
Work
By Jasmine, East
By Nick, West
Wnet on Block
18.Karl pushes East on a block with a force of 125 N. While the block moves, the force of
friction between the block and the floor is 35 N. Karl pushes the block 55 meters.
a. What object performs work to the East? _________________ WEast = ___________
b. What object performs work to the West? _________________WWest = ___________
c. Wnet performed on the block? ________________________
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Work and Energy.doc
Physics, Mr. Kent
Quiz: Work
Name: ________________________________
*** You can use anything in your notebook EXCEPT today’s Daily Worksheet ***
1. What is the formula for Work? _______________ The SI-Unit for Work? __________
2. Define Work in words: ___________________________________________________
3. Lyman exerted 60 N to pull a cart 40 m down the street. How much work did he
do? _________________
4. Jasmine did 5,000 j of work pushing a branch 6.5 meters across her deck. How force
did she exert? _________________
5. By exerting a force of 50,000 N a crane did 2.7 million j of work to lift truck. How far
was the truck lifted? _________________
6. During a workout, Lindsay lifts a 50 kg barbell 0.45 m upward.
a. What force did she exert? ______________________
b. How much work did she perform? ____________________
7. An elevator transported Mark (75 kg), Linda (60 kg) and Phil (70 kg) from the first floor of a
building to the 12th floor. Each story of the building (distance from one floor
to the next) is 12 feet. How much work did the elevator perform? _________________
9. Mitch drags a 350 kg block East across a frictionless floor for 50 m by exerting a force of
110 N. He then turns around and, without changing force, he pushes the block West
15 m. Weast: _____________ Wwest: _____________ Fnet: _____________
10.Lillian pulls a 250 kg object 75 meters across a floor with k of 0.62 by exerting a force of
2,000 N.
Normal Force? _____________ fk?______________
Work performed by Lillian? ____________ Work performed by friction? ___________
Net Work? _________________
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Work and Energy.doc
Physics, Mr. Kent
Daily Worksheet: Mechanical Energy
Name: ________________________________
1. Definition of Work: ____________________________________________________
2. Formula for work: ________________________ SI-Unit: ___________ (_____)
3. Be careful! w is the symbol for _____________ and W is the symbol for ___________
4. How much work does the gnome below perform on the block? _______________
5. When work is upward (lifting), the force is: ___________________________________
6. Roger lifts an 8 kg block 0.35 m from the floor. Work performed by _____________.
Work performed on ________________. Won_the_block = _______________.
7. A gnome pushes a block with a force of 80 N to move it 90 meters East. He then turns
around and pushes the same block West 70 meters with a force of 65 N.
WEast = _____________ WWest = _____________ WNet on the block = ____________
8. Is work performed by the
weightlifter on the left? _______
How about the weightlifter on the
right? __________. Explain using
the formula W = Fd.
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Work and Energy.doc
9. There are several different types of Energy:
_____________________ _____________________ _____________________
_____________________ _____________________ _____________________
_____________________ We will focus this week on ______________________
10.We’ll consider 2 types of Mechanical Energy: _____________________ (_______) and
___________________________________ (_______). ______ + _______ = _______
11.The SI-Unit for Energy is the __________, the same as for _____________.
12.So, just as with Momentum and Impulse we can add ___________ and _____________
Final Energy = ____________
Final Energy = ____________
13.Energy can be converted to __________, that is it can exert a __________ over a
__________________.
14.Definition of Energy: ___________________________________________ that is
______________________________________________________________________
15.____________ energy is the energy of ______________. Formula: ______________
16.A 0.9 kg toy race car is travelling at 6 m/s. Kinetic Energy: ________________
17.A race car travelling at 8 m/s has 24 J of kinetic energy. Mass: ____________
18.A 2.4 kg rock is dropped from a tall tower. What is its Kinetic Energy 3.5 seconds
after it is dropped? _________________
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Work and Energy.doc
19.______________ energy is _____________ energy. That is, it is energy that can be
_________________ to perform work. Some examples:
__________________________________ __________________________________
__________________________________ __________________________________
20.How is energy stored as potential energy during a fishing cast? ___________________
______________________________________________________________________
21.When you cast a fishing rod, you must cast enough _____________ to cause the rod to
flex ___________________ at the back of the cast. This is called _________________
the rod & is when ______________________ is stored in the rod. During the forward
stroke ___________________ in the rod is converted to ____________________ of the
bait or lure.
22.Why is thick, massive line used in fly fishing? ________________________________
______________________________________________________________________
23.An object with Gravitational Potential Energy has the ability to do work because it can:
____________, __________________, ________________ & _______________________
GPE is called the energy of ____________________.
24. The ball on the table has _______________
energy. When the ball falls from the table
this energy is converted to ____________
energy which enables the ball to do
__________ on the ____________ which
is a simple machine called a ___________
that does work on ___________________.
25.Formula for GPE: ____________________
26.A 65 kg person stands on the top of a 10 m tall building. GPE: ___________________
27.A 110 kg object as 4,312 J of Gravitational Potential Energy. Height: ______________
28.Formula for Mechanical Energy: _____________________________
29.One last thing about GPE: GPE is ______________ to a bottom level that ________
pick. Since height will vary by the bottom level, GPE will vary too.
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Work and Energy.doc
Physics, Mr. Kent
Class Work: Mechanical Energy
Name: ________________________________
1. Provide the type of energy for each situation:
a. An atom bomb “splits’ an atom:
_____________________
b. A person eats a meal and gains energy for activity: _____________________
c. A person turns on a light bulb:
_____________________
d. A bow is drawn back before shooting an arrow:
_____________________
2. The definition of energy: _________________________________________________
3. The SI-Unit of energy: _______________ The same as ______________
4. There are two types of mechanical energy:
a. _____________ energy (____)
b. ________________________ energy (______)
5. Formula for Mechanical Energy: ME = _________ + _________
6. Kinetic Energy is the energy of ___________________. Formula: ________________
7. A 1.5 kg ball is rolling at a constant 4.5 m/s. KE? ____________________
8. A 75 kg object has 5,400 J of Kinetic Energy. Velocity? _________________
9. John (90 kg) stands at rest talking to his brother. KE? _______________
10.What is the name for energy that is stored? _________________ energy
11.Provide brief descriptions for 4 situations in which energy is stored as potential energy:
a. ______________________________________________________________
b. ______________________________________________________________
c. ______________________________________________________________
d. ______________________________________________________________
12.How is potential energy stored in a fishing rod? _______________________________
13.What is the formula for Gravitational Potential Energy? _________________________
14.A 25 kg object sits on a shelf 2.5 m above a classroom floor. GPE? _______________
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Work and Energy.doc
15.A 45 kg object has 8,820 kg of GPE. Height? _____________________
16.An object on a ledge 175 m above a valley floor has 85,750 J of GPE. Mass? _______
17.A 2.5 kg ball sits on the top of a school. Beneath the ball, there are 2 physics classes being
taught:
a. One on the 2nd floor of the school 3.5 m below the ball
b. One on the 1st floor of the school 6.6 m below the ball
What GPE will the students in the 2nd floor class calculate for the ball? ____________
What GPE will the students in the 1st floor class calculate for the ball? ____________
18.A 1.25 kg squirrel walks across a clothes line 2 m above a lawn at a velocity of 1.5 m/s.
KE = ___________ GPE = ___________ Mechanical Energy (ME) = ___________
19.A 5 kg rock falls toward the ground. 5 m above the ground, it is travelling at 12 m/s.
KE = ___________ GPE = ___________ Mechanical Energy (ME) = ___________
20.Linda plays around with a 4 kg ball in her kitchen
a. She lifts the ball from the floor to the top of a 1.4 m tall table.
b. The ball sits motionless on the table.
c. Linda pushes the ball causing it to roll at 1.5 m/s halfway across the table.
d. Just as the horizontal velocity of the ball falls to 0 m/s, the ball falls off of the table.
e. Half way to the ground the ball is travelling at 3.7 m/s.
f. Just before reaching the ground the ball is travelling at 5.2 m/s.
How much work was done by Linda between in step a? _______________.
Complete the following table to calculate total mechanical energy at b - f
Position
Kinetic Energy (KE)
Gravitational Potential
Total Mechanical
Energy (GPE)
Energy
b
c
d
e
f
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Work and Energy.doc
Physics, Mr. Kent
Quiz: Mechanical Energy
Name: ________________________________
1. Name 3 types of energy other than Mechanical, Kinetic and Gravitational Potential energy:
______________________ ______________________ _______________________
2. Kinetic Energy is the energy of ____________________
3. A 15 kg dog is trotting at 6.5 m/s. Kinetic Energy? ______________
4. A 4 kg cat has 18 J of Kinetic Energy. Velocity? ____________
5. Gravitational Potential Energy is the energy of ____________________
6. Name three situations in which Potential Energy is stored. Example: Stretching a spring
(Sorry – you can’t use that one).
a. ______________________________________________________________
b. ______________________________________________________________
c. ______________________________________________________________
7. A 7.5 kg ball sits on a shelf 2.4 m above the floor. GPE? ______________
8. A ball that has GPE of 411.6 J rests 12 meters above the ground. Mass? ____________
9. In this building each story of the building is 4 meters in height (from the floor of one story to
the floor of the next story). Mr. Kent stores a 3.5 kg box on a shelf 2.25 m above the floor of
his room on the second floor. The students in his classroom and the classroom beneath him
calculate the GPE of the box from their perspective.
a. GPE from the perspective of Mr. Kent’s students:
___________
b. GPE from the perspective of the students in the room below Mr. Kent: ___________
10.A 65 kg person walks at a speed of 4.5 m/s on the roof of a 20 m tall building.
KE = ___________ GPE = ___________ Mechanical Energy (ME) = ___________
11.Bill exerts a force of 200 N to push a 50 kg desk 12 m East across a tile floor (k = 0.35)
He then turns around and pushes the desk West 5 m using the same force.
Work done on the desk:
Wfriction west = ________
WEast Bill = ________
WWest Bill = ________
Wfriction east = ________
WNet = ________
Work done by Bill: ________________
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(tot work on desk)
Work and Energy.doc
Physics, Mr. Kent
Daily Worksheet: Mechanical Energy #2
Name: ________________________________
We’ve seen four things in our study of Energy:
1. ___________________ In words: ______________________________________
Formula: __________________ SI-Unit: ______________________
2. ______________ Energy (______). In words: ________________________________
Formula: __________________ SI-Unit: ______________________
3. __________________________ Energy (______) In words; _____________________
_____________
Formula: _________________ SI-Unit: ______________________
4. _________________ Energy (______)
Formula: ____________________ SI-Unit: ______________________
Questions 5 - 10: Draw a picture here. Add pieces as you go.
5. P1: A 1.5 kg ball sits stationary on the floor (zero level).
KE ________ + GPE = ________ = ME ________
6. P2: The 1.5 kg ball is lifted to the top of a 1.2 m high table where it is stationary.
KE ________ + GPE = ________ = ME ________
7. P3: The ball is pushed, causing it to roll with v = 1.6 m/s.
KE ________ + GPE = ________ = ME ________
8. P4: Friction slows the ball which comes to rest at the far edge of the table.
KE ________ + GPE = ________ = ME ________
9. P5: The fall rolls off the table edge. Half way down, it’s travelling at 3.43 m/s.
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Work and Energy.doc
KE ________ + GPE = ________ = ME ________
10.P6: The ball comes to rest on the floor (zero level)
KE ________ + GPE = ________ = ME ________
11.Between P1 (stationary on floor) and P2 (stationary on table) the ball acquired 17.6 J of
_____________ and thus 17.6 J of ______________. The ball acquired this energy
because ________________________________. The work to ________ the ball:
F = __________ x _______ = __________ W = ________ x ________ = __________
The work done on the ball gave the ball its ______________.
12.Explain how the ball acquired its Kinetic Energy in P3.
13.Whenever the energy of an object changes ___________ has been done on it. In fact,
the __________ way for an object’s energy to change is via the _________ done on it.
Questions 14 and 15 pertain to the following picture:
3.834 m/s
14.Complete this table to show what types of energy exist at positions P1 to P4.
Position
KE? (y/n)
GPE? (y/n)
P1
P2
P3
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ME? (y/n)
Work and Energy.doc
P4
15.Complete this table to provide the magnitudes of the energies at positions P1 - P4.
Position
KE (Joules)
GPE (Joules)
ME (Joules)
P1
P2
P3
P4
16.Just like momentum, Mechanical Energy is ________________. If the only force
exerted on an object is _______________ then no ME is _________________ and no
ME is ___________________ (ME stays _________________)
17.A stationary 1.5 kg ball sits at the edge of a 1.2 m high table (P1). The ball falls off.
Consider P2 to be just before the ball reaches the ground.
P1:
GPE __________ + KE __________ = ME __________
P2: Vf = __________ GPE __________ + KE __________ = ME __________
Was Mechanical Energy conserved? ______
18.Use the principle of Conservation of Energy to find v at the bottom of the coaster.
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Work and Energy.doc
250 kg
19.Draw the picture from the previous problem with one change: vtop = 3.5 m/s. Find v
at the bottom
18.Draw the picture from the previous problem with these changes: (a) DO NOT draw the car
at the bottom (height = 0). (b) Rather, draw a cart at the top of the smaller, 15 m hill. Find v
at the top of the small hill.
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Work and Energy.doc
Physics, Mr. Kent
Class Work: Mechanical Energy #2
Name: ________________________________
1. A 250 kg roller coaster car at a 25 m high peak in its track is travelling at 3.5 m/s. Ignoring friction, what it
the car’s velocity after it has travelled down the slope to a point at elevation = 0 m? Draw the
track and solve for velocity. v = _______________
2. A 400 kg roller coaster car at a 30 m high peak in its track (the top) is travelling at 6 m/s. As it travels along
the track, the force of kinetic friction is 600 N. The car rolls down a 45 m length of track to reach an
elevation of 0 meters (the bottom).
Mechanical Energy of the car at the top: ____________________________________
Work done by friction on the car: _______ x ________ = ______________
Total mechanical energy of the car at the bottom: _______________ vbottom = __________
3. A 400 kg travels through a low point in the track (elevation = 0) at 25 m/s. It then climbs a 60 m hill to
reach a high point with elevation = 20 m. During that climb, the force of friction is 500 N.
Mechanical Energy of the car at the bottom: ________________________________
Work done by friction on the car: _______ x ________ = ______________
Total mechanical energy of the car at the top: ________________ vtop = _______
4. A 500 kg roller coaster car travels at 1.5 m/s at the top of a 20 m peak in its track. It descends an 80 m
section of track to an elevation of 0 m and then travels along a 100 m horizontal section. The force of
friction is 450 N. After the flat section (Position 2), the car strikes a shock absorber that brings it to a halt in
1.2 seconds. At that point a chain driven system lifts the car does 170,000 J of work to lift the car to the
highest peak on the track where it travels at 0.5 m/s before plunging down scaring the daylights out of the
passengers.
KEi = ___________ GPEi = ___________ MEi = ___________ Wfriction = __________
Position 2: ME = __________________ v = _________________ p = __________________
Re: the shock absorber: J = _____________________ F = ____________
Highest Peak: KE = ________________ GPE = _________________ h = _____________
5. Mr. Kent’s Physics class builds a “Rube Goldberg” track which uses a 0.75 kg ball. The track sits on a
table. At the start, the ball is placed in a carrying bucket that rests on the table. When a student turns a
crank, the ball is lifted to a height of 0.8 m to Point 1 where it sits idle for a moment. The ball then rolls
through a ridiculously windy 2.5 m track with a coefficient of kinetic friction of 0.03 with the rolling ball.
At the end of this track (Position 2), the ball is 0.65 m above the table and it falls toward the ground,
triggering a bunch of crazy events, that end up punishing Mr. Bill.
Work performed by the bucket: ______________ Point 1 ME: ________________
fk = ____________ Wfriction = ____________
Point 2: ME = ____________ KE = ___________ v = _____________
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Work and Energy.doc
Physics, Mr. Kent
Quiz: Mechanical Energy #2
Name: ________________________________
Questions 1 - 5: Draw a picture from the following description. Then calculate Kinetic,
Gravitational Potential and Mechanical Energy at the positions described (P1 – P5).





P1:
P2:
P3:
P4:
P5:
A 3.5 kg ball sits stationary on the right edge of a 2.4 m book shelf.
The ball falls off the bookshelf to position 1.5 meters below P1
Mr. Kent catches the ball an places is on the floor where it is stationary
Mr. Kent kicks the ball causing it to accelerate go 3 m/s.
The ball climbs a 0.5 m high ramp. At the top (P5) it is travelling at 1.2 m/s.
1. At P1: KE: ____________ GPE: ____________ ME: ____________
2. At P2: KE: ____________ GPE: ____________ ME: ____________
3. At P3: KE: ____________ GPE: ____________ ME: ____________
4. At P4: KE: ____________ GPE: ____________ ME: ____________
5. At P5: KE: ____________ GPE: ____________ ME: ____________
Questions 6 - 8: Draw a picture of a roller coaster for each question. Then answer the
questions.
6. A 175 kg roller coaster car sits stationary at the top of a 35 meter peak of a roller coaster
track. The car rolls down the sloping the track until it reaches the bottom of the
track (height = 0). What is the velocity of the car at this point? _______________
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Work and Energy.doc
7. A 175 kg roller coaster is travelling at 4.5 m/s at the top of a 35 meter peak of a roller
coaster track. The car rolls down the sloping track, past a bottom point, and up to the
top of a 25 meter peak. What is the velocity of the car at this point? _______________
8. A 175 roller coaster car is travelling unknown velocity at the top of a 35 meter peak of a
roller coaster track. The car rolls down the sloping track, past a bottom point, and up to the
top of a 25 meter peak where it is travelling at 5 m/s. What was the car’s speed
at the top of the 1st peak (35 meter)? __________________
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Work and Energy.doc
Physics, Mr. Kent
Work/Energy Review Notes
1. Work
a. Force exerted over distance
b. W = Fd
c. Unit of measure: Joule (j)
2. Horizontal Work
a. Force is a push or pull
3. Vertical Work
a. Force is the weight of the object
b. Upward: Force exerted to overcome force of gravity
c. Downward: Force of gravity
4. Net Work
a. Unless work is done in opposite directions it is positive (left side below).
b. If work is done in opposite directions one is positive and one is negative
i. Work done on an object: Add positive & negative work (Net Work)
ii. Work done by the pushers/pullers: Positive
5. A classic example of negative work is work done by friction
a. While an object is moving Kinetic Friction pushes back (against movement)
b. fk = kFN
c. When a person pushes an object and overcomes friction:
i. The person does positive work
ii. The friction does negative work
iii. Net Work = the sum of the positive and negative works
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Work and Energy.doc
6. If there is no distance, there is no work!
a. Example: A weightlifter holding a huge weight over his head BUT NOT MOVING
IT has done no work.
7. There are 7 types of energy. We will concern ourselves solely with Mechanical which has
two sub-types of energy:
a. Thermal
b. Chemical
c. Electric
d. Radiant
e. Nuclear
f. Magnetic
g. Mechanical
i. Kinetic
ii. Potential
8. Energy is the potential to do work
9. Kinetic Energy (KE):
a. The energy of motion
b. KE = ½mv2
10.Potential Energy is stored energy
11.Gravitational Potential Energy (GPE):
a. The energy of position
b. “Up in the air”
c. Can fall and do work
d. GPE = mgh
e. GPE is measured from an arbitrary “zero level”
i. Usually obvious in a problem
ii. Still, you can choose zero level
12.Mechanical Energy (ME) is the sum of KE and GPE
a. An object can have both (moving above zero level)
b. ME = KE + GPE
13.Whenever the energy of an object changes it has had work done on it
a. Example:
i. Stationary ball on floor:
KE = 0, GPE = 0, ME = 0
ii. Ball is lifted to a tabletop. 17.6 of work done on it
iii. Stationary ball on table:
KE = 0, GPE = 17.6, ME = 17.6
14.Just as we saw with momentum, the Mechanical Energy of an object is conserved
a. IF the only force acting on that object is gravity
b. No ME is created and none is destroyed
c. As an object changes position and velocity, however, energy DOES move back and
forth between KE and GPE (but ME is constant – conserved)
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Work and Energy.doc
15.Conservation of Energy problems
a.
b.
c.
d.
e.
f.
g.
KEi = ½mvi2 =
GPEi = mghi = 250(9.8)(25) =
MEi = 0 + 61,250 =
`
2
KEf = ½mvf =
GPEf = mghf =
MEf = ½(250)vf2 + 0 =
`
MEi = MEf 
0 J because no motion (vi = 0)
61,250 J
61,250 J
½(250)vf2
0 J because at zero level (hf = 0)
½(250)vf2
61,250 = ½(250)vf2 vf = 22.14 m/s
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Work and Energy.doc
Physics, Mr. Kent
Work/Energy Review Quiz/Test
Name: ______________________________________
1. Jill exerted 60 N to pull a cart 70 m down the street. How much work did she
do? _________________
2. Mary did 12,000 J of work pushing a branch 5 meters across her deck. How force
did she exert? _________________
3. By exerting a force of 70,000 N a crane did 3.2 million J of work to lift truck. How far
was the truck lifted? _________________
4. During a workout, Winifred lifts a 30 kg barbell 0.6 m upward.
a. What force did she exert? ______________________
b. How much work did the perform? ____________________
5. A 35 kg rock falls 54 m from the top of a cliff.
a. What object performed work on the rock? ________________
b. How much work? _______________
6. Bob and Roger push on opposite sides of a block resting on a frictionless surface. Bob
exerts a force of 250 N to the South and Roger exerts a force of 160 N to the North. The box
moves 15 m South.
Work done on the box:
By Bob: _____________ by Roger: _____________ Net Work: _____________
Work done by Bob: _____________ Work done by Roger: _____________
7. Linda pushes west on a 50 kg block resting on a cement floor. After she gets the block
moving, she pushes with a force of 250 N. The coefficient of kinetic friction (k) between
the block and the floor is 0.35. The box moves 15 m to the West.
Friction force (fk): ______________
Work done on the box:
By Linda: _____________ by friction: _____________ Net Work: _____________
Work done by Linda: _____________ Work done by friction _____________
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Work and Energy.doc
8. Rebecca pushes East on a 75 kg block with a force of 195 N. Her son Mark pushes West
with a force of 25 N. The coefficient of kinetic friction (k) is 0.2. The block
moves 25 m East. Net work done on the box: ________________ (show work!)
Questions 9 – 12: Name the type of energy.
9. Released during the bomb that destroyed Hiroshima in WWII:
______________
10.Stored in food:
______________
11.Firewood is burned in a fireplace
______________
12.A switch is thrown, turning on a light in a dark room
______________
13.Name 3 situations in which potential energy is stored (use a phrase or a short sentence
DON’T JUST SAY “Baseball pitcher”).
a. ___________________________________________________________________
b. ___________________________________________________________________
c. ___________________________________________________________________
14.A 0.6 kg toy truck rolls across the floor at 0.4 m /s
KE: _____________ GPE: _____________ ME: _____________
15.A 1.2 ball sits stationary on a 1.3 m high table:
KE: _____________ GPE: _____________ ME: _____________
16.A 3.5 kg dog walks on top of a 2 m high wall at 1.4 m/s.
KE: _____________ GPE: _____________ ME: _____________
17.A 5.5 kg rock falls off a 50 m high cliff. At and elevation of 20 m:
Vf: _____________KE: _____________ GPE: _____________ ME: _____________
Momentum (p): ______________
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Work and Energy.doc
Problems 18 – 20: Draw a picture from the problem. Label that picture with the
information from the problem. Solve. ** Show your work ***
18.A 700 kg roller coaster car is stationary at the top of a 45 m high peak in its track. It rolls
down to the bottom of the track. What is the velocity of the car at the bottom?
Velocity at bottom: ___________________
19.A 900 kg roller coaster car is travelling at 2.4 m/s at the top of a peak in its track of unknown
height. It rolls down to the bottom of the track and then climbs a 30 m peak
where it is travelling at 3.6 m/s. What is the height of the first peak? _____________
20.An 800 kg roller coaster car is travelling at 20 m/s at the top of a 60 m peak on its track. It
rolls down to the bottom of the track and then climbs a second, 100 m high peak. To
what elevation can the car climb on this second peak? ___________________
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