Download Review Game – Fly swatter questions

Review Game – Fly swatter questions
Newton is a unit for …
Force and Weight
Watts is the unit for…
Power
Kilograms is the unit for …
Mass
Joules is the unit for …
Energy (potential, kinetic) or Work
The Energy of motion is …
Kinetic Energy
When the skater is at the bottom of the half-pipe, the _______ energy is at its maximum Kinetic Energy
What states that energy cannot be created nor destroyed?
Law of conservation of energy
When a skater loses speed on the half-pipe, this loss of energy is due to ______
friction
When the skater is at the top of the half-pipe, the _______ energy is at its maximum
Stored Energy due to an objects position is …
Grav PE
A boulder on the edge of a cliff is an example of which energy form?
Grav PE
Grav. PE
What is the kinetic energy of a 123kg skateboarder moving on a ramp at 8.2 m/s?
KE = ½ mv2
KE = ½ (123)(8.2)2
4135.3 J
Calculate the KE of a 1.1kg car, coming down from the top of a 2m hill, just as it reaches the bottom of the hill
if the car was traveling at 2.1 m/s.
KE =1/2 mv2 KE = ½ (1.1)(2.12)
2.43J
A small boat is moving at a speed of 4.3m/s in the water. The KE of the boat is 1700J. What is the mass of the
boat? EK = ½ mv2
1700 = ½ m(4.3)2
1700=9.245m
183.88kg = m
What is the gravitational potential energy of a boulder that is 300kg and is at the edge of a cliff 250m from the
ground?
PE =mgh
PE =(300)(9.8)(250)
735,000J
How much potential energy will an 85 kg football player have at the top of a 10 m high hill?
PE = mgh
PE = (85)(9.8)(10)
8330 J
A boy lifts a 3.2kg book from his desk, which is 1.8m high, to a bookshelf that is 2.9m high. What is the
potential energy relative to the desk?
PE = mgh
PE = (3.2)(9.8)(1.1)
PE = 34.496J
An diver has 15000 J of potential energy on top of the diving board. Assuming no energy loss, how much
kinetic energy does the diver have as he hits the water?
15000 J
(no math)
An arrow in a bow has 70 J of elastic potential energy. Assuming no energy loss, how much kinetic energy
does the arrow have after it has been shot?
70 J
(No math)
How much work is done when a 100N force is applied to move a 15kg object a horizontal distance of 5m at
constant speed?
W = fd
W = (100 N)(5 m) = 500 J
How much work is done when an upward force is applied to lift a 15kg object to a height of 5m at a constant
speed.
W = Fd
W=mgd
W = (15kg)(9.8)(5 m)
735 J
How much work does it take to push a 2kg mass across a horizontal displacement of 7m while using a force of
5N?
W=Fd
W = (5N)(7m)
W = 35J
A 74.3 kg diver steps off a 6.0m diving platform ignoring air resistance, what is the velocity of the diver as she
enters the water? (2 step)
PE = mgh
(74.3)(9.8)(6) = 4368.84J
KE = ½ mv2
4368.84 = ½(74.3)v2
10.84m/s
A 0.50kg sphere at the top of an incline has the potential energy of 6.0J relative to the base of the incline.
Rolling halfway down the incline will cause the sphere’s potential energy to be?_________
3.0J
A constant force of 20N applied to a box causes it to move 4 m at a constant speed of 4m/s. How much work is
done in the box in 6 seconds?
W =F d
W = 20*4
W = 80J
80J * 6 seconds
480J
What is the kinetic energy of a 2500 kg car traveling 20 m/s?
EK (KE) =1/2 mv2
KE =1/2 (2500)(20)2
500,000 J
A winch on a boat pulls a 50N anchor up 2 meters in 80 seconds.
How much work does the winch do to pull the anchor up out of the water?
W=Fd
W = (50N)(2m)
W = 100J
What is the power rating of the boat?
W=Fd
W = (50N)(2m)
W = 100J
P = W/t
P = 100J/80sec
P = 1.25W
How much gravitational potential energy does the anchor gain as it is lifted?
EP (PE) = m g h
Ep = F h
Ep = (50N) (2m)
Ep = 100J
A bulldozer does 30,000 J of work to lift a boulder a distance of 25m. How much did the boulder weigh(N)?
W=Fd
30,000J = F 25m
1200
A window washer stands on a scaffolding 30m above the ground. If he did 23,520J of work to reach the
scaffolding, what is his mass?
W=Fd
W=mgd
23,520 = (m) (9.8) (30m)
80kg
A motor does 5000J of work in 20s. What is the power of the motor?
P = W/t
P = 5000/20
250W
A 1000W microwave oven takes 90s to heat up a bowl of soup. How many Joules of energy does it use?
Remember Joules of energy = work so P = W/t
Doubling the velocity of an object will _______ its kinetic energy.
EK =1/2 mv2 EK =1/2 (1) (1)2 EK = 1
EK =1/2 (1)(2)2
1000W= W/90s
11.11J
EK = 4 so it would quadruple
Doubling the position of an object above a given reference level will _______ its potential energy.
PE = m g h
PE = (1)(1)(1) 1J
PE = (1)(1)(2)
2J so it would double
Be able to solve for and know the units for:
Kinetic Energy, Potential Energy, Mechanical Energy, velocity, mass, height, work, power, force, distance
Be able to define and example of:
Energy, Kinetic Energy, Potential Energy, Mechanical Energy, velocity, mass, height, work, power, force,
distance
Understand the Law of Conservation of Energy and be able to apply the concept to problems
Label and calculate the potential and kinetic energy off of diagrams. Be able to label (in percentage or Joules)
the potential energy, kinetic energy, or total mechanical energy at each point on the graph.