Download Physics Final Review Problems 2014 *Note: the following problems

Physics Final Review Problems
2014Final
Physics
Exam 2013 Equation Sheet
Kinematics
x f  x o  vt
x f  xo  vo t 
Energy
W = Fd
1
K  mv 2
2
U g  mgh
1 2
at
2
v f  vo  at
vf
2
 vo2  2ad
Freefall: a  g  9.8m /s2








Dynamics
F
a  net
m
Fg = mg
F1on2  F2on1
Fs//  sN
Fk //  k N
d  vt
1
h  gt 2
2






DC Circuits
I = V/R

V2
P  IV 
 I 2R
R



Universal Gravitation
FG = Gm1m2/r2
G = 6.67 x 10-11 N m2/kg2
Series Circuit
ITotal  I1  I2  I3  ...
RTotal  R1  R2  R3  ...
Parallel Circuit
ITotal  I1  I2  I3  ...
V  V1  V2  V3  ...


I  Ft
Ft  mv
m1v1i  m2v 2i  (m1  m2 )v f
Pinitial = Pfinal
k  9x10 9 N
V  V1  V2  V3  ...
Static Equilibrium
m1v1i  m2v2i  m1v1 f  m2v2 f
q1q2
d2
Fq1 onq2  k

p  mv
W
t
Electrostatics and Electric Fields
Circular Motion
v2
ac 
r
Fc  mac
V = 2πr/T
Momentum

P
2D Motion
F1d1  F2d2



1
RTotal

1
1
1


 ...
R1 R2 R3
m2
C2
Physics Final Review Problems 2014
*Note: the following problems are a general overview of what we have learned. Going
through your notes, textbooks, old quizzes, old tests, and possibly even some labs will aide in
your studying for the final exam. The exam will not be identical to this study guide; this is
merely an aid to your preparation.
Kinematics
Be able to do/answer the following:
a) Draw a motion diagram for a moving object
b) Interpret the type of motion of the object using a dot diagram. What does a dot
diagram look like for an object that is traveling fast vs. one that is moving more
slowly?
c) What does a dot diagram look like for an object that is traveling with a constant
velocity vs. speeding up vs. slowing down?
d) Determine the direction of acceleration using a motion diagram
e) Be able to do the above with graphical representations as well (position vs time
graphs, velocity vs time graphs)
f) Calculate velocity, position, and acceleration using the appropriate formulas.
1. What is the difference between distance and displacement? Speed and velocity?
2. What type of motion does a straight line on a position vs. time graph represent?
What type of motion does a curved position vs time graph represent? Explain. Be able
to do the same with velocity vs time graphs.
3. Find the acceleration of an object that comes to a stop over 12 seconds. The initial
velocity at the beginning of the 12 seconds is 240 m/s.
4. Albert walks 4 blocks north, stops for a rest, and then walks 9 more blocks east.
He’s tired and stops again before he walks another 6 blocks west. What is his
displacement in blocks? What is the path length of his trip?
5. If you throw a tennis ball straight up in the air with a velocity of 30m/s, how long will
it take to come back to the ground? What is the acceleration of the ball when at the
tippy-top of the flight?
6. What is terminal velocity?
7. A boy on a 250 m high bridge kicks a rock horizontally. It lands 100 m away.
a) How long (in seconds) does the rock take to hit the ground?
b) What was the initial velocity of the rock?
Forces and Newton’s Laws
Make sure you know how to:
a) Describe all of Newton’s Laws.
b) Identify a system, construct a force diagram for it, and use the force diagram to apply
Newton’s second law. Be able to explain and represent the relationship between
force and acceleration.
c) Be able to identify Newton’s 3rd Law pairs in specific situations.
Physics Final Review Problems 2014
8. Why do you need to keep pushing a grocery cart in a store in order to keep it moving?
9. Thomas is riding an elevator. His mass is 76.0 kg. If a scale upon which he is
standing reads 955 N, what can you say about the motion of the elevator? Draw a
motion diagram, a force diagram, and evaluate all forces and acceleration. What is
Thomas’s weight?
10. Identify third law force pairs for the following interactions: A rollerblader and the floor,
a volleyball player and the volleyball, and a speeding up car’s tires and the road.
11. What is the difference between mass and weight?
12. A 32-kg vacuum cleaner moves over a carpeted floor with an acceleration of .75
m/s2. If the coefficient of kinetic friction between the vacuum cleaner and the carpet
is 0.30, what is the force applied to the vacuum cleaner?
Circular Motion
13. When an object is moving in a circle, can speed be constant? Is velocity constant?
What’s the direction of the acceleration? What’s the direction of the force?
14. A 5 kg metal ball is swung in a circle attached to a 1 meter chain. The ball is traveling
at 5 m/s.
a. Determine the centripetal acceleration of the ball
b. Determine how hard you need to pull on the chain to maintain this rotation.
Static Equilibrium
15. A meter stick (100 cm) is supported at the 50 cm mark. A 20 g mass sits on the 20
cm mark, a 40 g mass sits on the 40 cm mark, a 60 g mass sits on the 60 cm mark,
and an 80 g mass sits on the 80 cm mark. Where would a 150 g mass need to be
located in order to balance the system? (cm)
16. Fred (95kg) sits 1.25 meters away from the middle of a seesaw. How far away
should another person (75kg) sit in order to balance out the see saw?
17. For the mobile balanced through the CG of each stick:
On the top level, a 30 g box is
placed 10 cm to the right of the
pivot point. What mass of box should be placed 15 cm to the left of the pivot point?
On the bottom level, a 20 g box is placed 20 cm to the right. Where should a 10 g mass be
placed to balance this?
Physics Final Review Problems 2014
Impulse and Momentum
Make sure you can solve problems using the conservation of momentum principle and the
impulse/momentum theorem
18. Two identical cars are traveling toward each other at the same speed. One of the
carts has a piece of modeling clay on its front. The carts collide, stick together, and
stop; the momentum of each cart is now zero. If the system includes both carts, did
the momentum of the system disappear? Explain your answer.
19. Robin Hood has a mass of 35kg and shoots a 0.1kg arrow at a speed of 150m/s,
causing him to move in the opposite direction. What is the recoil speed of the archer?
20. A 0.3-kg tennis ball traveling at 15 m/s is returned by Daria. It leaves her racket with
a speed of 44 m/s in the opposite direction from which it came.
If the racket and the ball are in contact for 0.05 s, calculate the average force the
racket exerts on the ball.
21. A carnival game requires you to knock over stuffed clowns at the NJ shore. You are
given the option of picking a ball that is very bouncy or a big lump of clay. Both
options have the same amount of mass. Assume you can throw them with equal
speed and accuracy and you only get one throw. Which option would you choose?
Why?
22. A 40 kg skater traveling at 4 m/s overtakes a 60 kg skater traveling at 2 m/s in the
same direction and collides with her. If they remain in contact after the collision,
what is their final velocity?
Work and Energy
Make sure you can:
a) Choose a system and the initial and final states of a physical process
b) Solve problems using kinetic/potential energy formulas
c) Apply energy conservation principles to solve problems.
d) Understand and apply the definition of work
23. If an object’s speed increases by a factor of 5, what factor would the kinetic energy
increase by?
24. In Metropolis, the comic book hero Superman uses his incredible strength to save
the lives of countless ordinary citizens. One day, the braking system on a passenger
bus fails when the bus is 50 m away from a busy intersection. The bus is moving
towards the intersection at 5 m/s. If Superman exerts a force of 300 N on the bus,
which has a mass of 1000 kg, will he be able to stop the bus before it reaches the
busy intersection?
25. A 4 kg. bowling ball is raised 15 m. to the top of a ramp. It is released from rest and
travels to the bottom.
a) How much PE does the ball have when it is at the top of the ramp? The
bottom of the ramp?
b) How fast is it traveling when it reaches the bottom (ignore friction).
26. A 51.7-kg hiker ascends a 43.2-meter high hill at a constant speed of 1.20 m/s. If it
takes 384 s to climb the hill, then determine:
a) The potential energy change of the hiker.
b) The kinetic energy of the hiker.
c) The work done by the hiker’s muscles.
d) The power generated by the hiker.
Physics Final Review Problems 2014
Gravitation
27. Determine the gravitational force between two objects that are 100 km apart if one
has a mass of 100 kg and the other has a mass of 6.5 x 1019 kg.
Electrostatics/Electric Fields
28. Are electrostatic interactions the same as magnetic interactions? What is similar?
What is different?
29. Determine the electrical force between two objects that are 100 km. apart if they
have a charge of one Coulomb and six Coulombs respectively.
30. Draw an electric field for 2 oppositely charged particles a small distance apart. Draw
an electric field for 2 positive charges. Draw one for 2 negative charges.
31. Two charged particles, A and B, are near each other, but not touching.
A
B
a. What will happen to the force exerted on each particle if the charge on A is
doubled?
b. What will happen to the force exerted on each particle if the charge on B is
doubled?
c. What will happen to the force exerted on each particle if the charge on each
particle is doubled?
d. What will happen to the force exerted on each particle if their separation distance
is doubled?
e. What will happen to the force exerted on each particle if the charge on A is
doubled and their separation distance is cut in half?
DC Circuits
Know definitions and units of charge, voltage, current, power, and resistance. Know the
differences between series and parallel circuits. Use Ohm’s Law to solve circuit problems.
32. What condition(s) are needed for electric charge to travel from one place to another?
In other words, what makes a working circuit?
33. Draw a circuit that consists of a 12-V battery with 3 resistors in series. One resistor is
200Ω, one is 150 Ω, and the last is 275 Ω. Calculate total resistance and total
current. Find the current in each resistor and the voltage drop across each resistor.
Find the power dissipated by each resistor. Now do the same thing with the three
resistors in parallel.