South Pasadena • AP Physics Name ______
Period ___ Date ___/___/___
PRACTICE TEST for Midterm Exam
FORMULASd = vt / d = vot + ½ at2 / d = t / v = vo + at / v2 = vo2 + 2ad
v = / q = tan–1 / vx = v cos q / vy = v sin q
dx = vxt / vy = voy + at / dy = voyt + ½ at2 / vy2 = voy2 + 2ady
F = ma / W = mg / P = / F = mgsinq / g = −9.8 m/s2
freq = / v = 2 π r (freq) / aC = / FC = / π = 3.14
FG = / FS ≤ μS N / FK = μK FN / G = 6.67 × 10–11 N·m2/kg2
p = mv / I = ∆p = m(v – v0) = Ft / pbefore = pafter
KE = ½ mv2 / PE = mgh / W = F·d = ∆KE / P = / KE = ½ mv2
IMA = = / AMA = / Eff = × 100% / PEbefore + KEbefore = PEafter + KEafter
Use these terms to identify each description given in terms 1-12 below:
· Acceleration / · Centripetal Acceleration / · Centripetal Force· Coefficient of Friction / · Displacement / · Distance
· Energy / · Force / · Force of Friction
· Frequency / · Gravitational Force / · Gravitational Potential Energy
· Impulse / · Kinetic Energy / · Mass
· Momentum / · Normal Force / · Position
· Power / · Pressure / · Speed
· Tension / · Time / · Velocity
· Weight / · Work
Description / Quantity / Vector/Scalar / Units
1 / A push or pull perpendicular to an object’s motion. / Centripetal force / Vector / N or
2 / The attraction between two objects due to their masses. / Gravitational Force / “Vector” / N or
3 / The change in an object’s kinetic energy. / Work / Scalar / J or
4 / The duration of an object’s motion. / Time / Scalar / s
5 / The force exerted over an area. / Pressure / Vector / Pa or
6 / The force exerted over time. / Impulse / Vector / N·s or
7 / The pull exerted on a string or rope. / Tension / Vector / N or
8 / The rate at which an object’s velocity changes. / Acceleration / Vector
9 / The rate at which momentum changes. / Force / Vector / N or
10 / The rate of change of an object’s position. / Velocity / Vector
11 / The stored energy of an object due to its height. / Gravitational Potential Energy / Scalar / J or
12 / The total length traveled by an object. / Distance / Scalar / m
2 · Kinematics: Motion in
One-Dimension
1. How long would it take a car, starting from rest and accelerating uniformly in a straight line at 5 m/s2, to cover a distance of 200 m?
a) 9.0 s c) 12.0 s
b) 10.5 s d) 15.5 s
2. A 0.100 kg rubber ball is thrown downward from the top of a building 30-m building with a speed of 4.0 m/s. How high above the ground is the ball after 2.0 s?
a) 2.4 m d) 22.0 m
b) 8.0 m e) 27.6 m
c) 12.2 m
3. Which of the following statements are about uniformly accelerated motion?
Select two answers.
a) If an object’s acceleration is constant then it must move in a straight line.
b) If an object’s acceleration is zero, then it’s speed must remain constant.
c) If an object’s speed remains constant, then its acceleration must be zero.
d) If the object’s direction of motion is changing then its acceleration is not zero.
4. On a horizontal number line, a fly is at the coordinate +6. The fly then flies and lands at the coordinate of –2. If the time traveled by the fly is 4 s, what is the fly’s velocity?
a) 2.0 units/s
b) 1.0 unit/s
c) –0.50 units/s
d) –1.0 unit/s
e) –2.0 units/s
5. A tennis ball is tossed vertically from the ground with a speed of 30 m/s. With what speed will the ball hit the ground?
a) 0 m/s d) 30 m/s
b) 10 m/s e) 40 m/s
c) 20 m/s
6. At a particular time, an object is moving with a velocity of –20 m/s and an acceleration of 20 m/s2. Which of the following is true about the object’s motion?
a) It is not moving.
b) It is speeding up (accelerating).
c) It is slowing down (decelerating).
d) Its speed is not changing.
e) It is both speeding up and slowing down.
3 · Kinematics in Two Dimensions (Projectile Motion & Vectors)
7. A ball was pitched with a speed of 40 m/s at an angle of 35° to the ground. What is the vertical component of the velocity of the ball?
a) 23 m/s d) 49 m/s
b) 33 m/s e) 70 m/s
c) 40 m/s
Questions 8-10: A football is kicked with a horizontal velocity of 20 m/s and a vertical velocity of 15 m/s.
8. What is the speed of the ball when it reaches its peak?
a) 0 m/s d) 25 m/s
b) 15 m/s e) 35 m/s
c) 20 m/s
9. What is the speed of the ball when it returns to the ground?
a) 0 m/s d) 25 m/s
b) 15 m/s e) 35 m/s
c) 20 m/s
10. How long does the ball travel in the air?
a) 1.5 s d) 5 s
b) 3 s e) 6 s
c) 4 s
* * * * * * * * * * * * * * * * * * * * * * * *
11. A stone is thrown horizontally with an initial speed of 30 m/s from a bridge. Find the stone’s total speed when it enters the water 4 seconds later. (Ignore air resistance.)
a) 30 m/s c) 50 m/s
b) 40 m/s d) 60 m/s
12. A soccer ball, at rest on the ground, is kicked with an initial velocity of 10 m/s at a launch angle of
30 °. Calculate its total flight time, assuming that air resistance is negligible.
a) 0.5 s c) 2 s
b) 1 s d) 4 s
13. Which one of the following statements is true concerning the motion of an ideal projectile launched at an angle of 45° to the horizontal?
a) The acceleration vector points opposite to the velocity vector on the way up and in the same direction as the velocity vector on the way down.
b) The speed at the top of the trajectory is zero.
c) The object’s total speed remains constant during the entire flight.
d) The vertical speed decreases on the way up and increases on the way down.
4 · Motion and Force: Dynamics
(Newton’s Three Laws of Motion)
14. A force of x newtons is applied to a crate on a frictionless surface, and the crate accelerates at 2.0 m/s2. What force (in newtons) should be applied for the crate to accelerate at 8.0 m/s2?
a) 0.5x
b) x
c) 2x
d) 3x
e) 4x
15. A 100-kg anchor is dropped in the water and falls at a constant speed of 4.5 m/s. What is the force of the resistance of the water encountered by the anchor?
a) 10.2 N d) 530 N
b) 22.2 N e) 980 N
c) 450 N
16. A ball is released and rolls down a rough ramp with an acceleration of 3.5 m/s2. Which of these forces is NOT acting on the ball?
a) The weight of the ball.
b) The force of the ramp pushing on the
ball.
c) The force of friction between the ball
and the ramp.
d) The force of the push.
e) All of the above act on the ball.
17. A person standing on a horizontal floor feels two forces: the downward pull of gravity and the upward supporting force from the floor. These two forces
a) have equal magnitudes and form an action/reaction pair.
b) have equal magnitudes but do not form an action/reaction pair.
c) have unequal magnitudes and form an action/reaction pair.
d) have unequal magnitudes and do not form
an action/reaction pair.
18. A person who weighs 800 N steps onto a scale that is on the floor of an elevator car. If the elevator accelerates upward at a rate of 5 m/s2, what will the scale read?
a) 400 N c) 1000 N
b) 800 N d) 1200 N
19. A frictionless inclined plane of length 20 m has a maximum vertical height of 5 m. If an object of mass 2 kg is placed on the plane, which of the following best approximates the net force it feels?
a) 5 N c) 15 N
b) 10 N d) 20 N
20. A 20 N block is being pushed across a horizontal table by an 18 N force. If the coefficient of kinetic friction between the block and the table is 0.4, find the acceleration of the block.
a) 0.5 m/s2 c) 5 m/s2
b) 1 m/s2 d) 7.5 m/s2
21. The coefficient of static friction between a box and a ramp is 0.5. The ramp’s incline angle is 30°. If the box is placed at rest on the ramp, the box will do which of the following?
a) Accelerate down the ramp.
b) Accelerate briefly down the ramp but then slow down and stop.
c) Move with constant velocity down the ramp.
d) Not move.
22. If all of the forces acting on an object balance so that the net force is zero, then
a) the object must be at rest.
b) the object’s speed will decrease.
c) the object’s direction of motion can change, but not its speed.
d) None of the above will occur.
23. Assuming a frictionless, mass-less pulley, determine the acceleration of the blocks once they are released from rest.
m
M
a) m g
M + m
b) M g
m
c) (M + m) g
(M – m)
d) (M − m) g
(M + m)
24. A block of mass m is at rest on a frictionless, horizontal table placed in a laboratory on the surface of the Earth. An identical block is at rest on a frictionless horizontal table placed on the surface of the Moon. Let F be the net force necessary to give the Earth – bound block an acceleration of a across the table. Given that g Moon is one-sixth of g Earth, the force necessary to give the Moon – bound block the same acceleration a across the table is
a) F/6 c) F
b) F/3 d) 6 F
25. A force F of strength 20 N acts on an object of mass 3 kg as it moves a distance of 4 m. If F is perpendicular to the 4 m displacement, the work it does is equal to
a) 0 J c) 80 J
b) 60 J d) 600 J
26. Under the influence of a force, an object of mass 4 kg accelerates from 3 m/s to 6 m/s in 8 s. How much work was done on the object during this time?
a) 27 J c) 72 J
b) 54 J d) 96 J
5 · Circular Motion and
Law of Gravitation
27. A 0.80-kg rubber stopper is connected to a string and makes a circular path. Which of the following requires the greatest tension on the string? (v = speed of the rubber stopper;
r = radius of the circular path)
a) v = 6.0 m/s r = 0.40 m
b) v = 6.0 m/s r = 0.80 m
c) v = 9.0 m/s r = 0.60 m
d) v = 12.0 m/s r = 0.40 m
e) v = 12.0 m/s r = 0.80 m
28. A person’s weight is the same on Titan (one of Saturn’s moons) as on Europa (one of Jupiter’s moons). However, Europa’s radius is half that of Titan’s. If the Europa has a mass of m kg, what is Titan’s mass?
a) 0.25m d) 2m
b) 0.50m e) 4m
c) m
29. When a car is banking a curve (assuming circular motion), which of the following is pointed in the same direction as the friction between the tires and the road?
I. Centripetal Acceleration
II. Centripetal Force
III. Instantaneous Velocity
a) I only.
b) II only.
c) III only.
d) I and II only.
e) I, II, and III.
(The Next Five Questions Are From the Chapter 5 Practice Test)
30. A ball is connected to a string and makes a circular path. The tension on the string (which is the centripetal force) is 6.0 N. If the radius remains constant and the velocity doubles, what will be the new tension on the string?
a) 1.5 N d) 12 N
b) 3.0 N e) 24 N
c) 6.0 N
31. A 0.020 kg rubber stopper is attached to one end of a string that is passed through a plastic tube. At the other end of the string weights are attached. A student whirls the rubber stopper in a horizontal circular path at constant speed, making ten revolutions every 4 seconds. If the radius of the circular path is 0.50 m, what is the centripetal acceleration acting on the stopper?