Physics
Name: ________________________
MIDTERM REVIEW
The exam is worth 100 points:
1 graph given data
100 multiple-choice questions/problems
Part I: Graphing
A. Shape
Relationship
Equation
Linear
“y” is directly related to “x”
y = kx
Parabolic
“y” is directly related to “x” squared
y = kx2
Hyperbolic
“y” is inversely (indirectly related to “x”
y = k/x
B. Position vs Time
At Rest
x
Constant Velocity
x
t
Constant Acceleration
x
t
t
Slope = velocity
C. Velocity vs Time
At Rest
Constant Velocity
v
Constant Acceleration
v
t
Slope = Acceleration
v
t
Area under curve = Displacement
t
D. Identify the type of motion for the time intervals listed below.
0 s – 1 s: ______at rest_____________
1 s – 2 s: ______constant acceleration (positive direction) _____________
2 s – 3 s: _______constant velocity (positive direction)_______________
3 s – 4 s: _______at rest_____________________
4 s – 5 s: ________constant velocity (negative direction)_____________
Find the velocity for each constant velocity.
2 s to 3 s: v = 2 m/s
4 s to 5 s: v = - 8 m/s
Part II: Multiple Choice
A. Chapter 2: One Dimensional Motion
1. Displacement of a round trip = ____zero______
2. Vector quantities have ___magnitude___ and _____direction____
3. Scalar quantities have only _______ magnitude _______.
4. A brick and feather are dropped from the same height at the same time in a vacuum.
Which will hit the ground first?
Both hit at the same time
5. A ball is thrown straight up at 4 m/s.
(A) What is the ball’s velocity at the peak? ____0 m/s_____
(B) What is the final velocity if the ball is caught at the same height? _ - 4 m/s__
(C) It reaches the peak in 0.41 s. How long is the ball in the air? __0.82 s___
Vave = x/t
x = vi t + 1/2 a t2
x = 1/2 (vf + vi) t
vf2 = vi2 + 2a x
vf = vi + a t
6. A train accelerates from 20 m/s to 35 m/s in 30 s. How far does it travel in this time?
x = 1/2 (vf + vi) t
Δx = ½ (20 m/s + 35 m/s)(30 s)
x = 825 m
B. Chapter 3: Two Dimensional Motion
1. Rock A and rock B are identical. Rock A is thrown horizontally from a tower just as
rock B is dropped from the same tower. Which rock will hit the ground first?
Both hit at the same time
2. All projectiles follow a ___parabolic____ path.
Horizontal
v f x = v ix + ax Dt
Dx = v ix Dt + 12 ax Dt 2
v fx 2 = v ix 2 + 2ax Dx
Vertical
v f y = v iy + ay Dt
y  viy t  12 a y t 2
v fy 2 = v iy 2 + 2ay Dy
3. A bird flies at 7 m/s west and the wind blows at 4 m/s south. What is the resultant
magnitude and direction of the bird’s velocity?
√
R = 8.06 m/s at 29.7 S of W
4. Find the x and y components of a soccer ball kicked at 22 m/s and an angle of 36
above the horizontal.
Vx = 22 m/s (cos 36)
Vy = 22 m/s (sin 36)
Vx = 17.80 m/s
Vy = 12.93 m/s
5. An object is thrown horizontally from a roof 13 m high. How long does it take to
reach the ground?
√
t = 1.63 s
C. Chapter 4: Force and Newton’s Laws
1. How does the mass of an object on earth compare to the mass of the same object on
the moon? How does the weight compare?
Mass is the same, Weight is less on the moon
2. An object’s inertia is directly related to its ____mass___.
3. Identify Newton’s Laws.
(A) For every action there is an equal and opposite reaction. ____3rd _____
(B) Acceleration is directly related to force and indirectly related to mass.
(F = m a) __2nd ______
(C) Objects in motion continues in motion and objects at rest stay at rest.
_____1st _____.
4. Give an example of a field force.
Gravity, Electrical, Magnetic
5. Give and example of a contact force.
Push, Kick, Friction
6. What are the two factors that affect the force of friction?
Texture and Normal Force (weight, mass)
7. What type of friction must you overcome to get an object to move? What type of
friction must you overcome to keep the object moving? Which type of friction is
always larger? Static, Kinetic, Static
8. What is the standard unit for mass in the MKS system? What is the unit for force in
the MKS system? Mass – kilogram (kg), Force – Newton (N)
F = m a
Wt = m g
9. What is the weight of a 60 kg person?
Fs = s FN
Wt = m g = -588.6 N
Fk = k FN
10. What is the mass of a 135 lb person?
m = Wt / g = 4.22 sl
11. A 15 N force accelerates an object at 2 m/s2. What is the mass of the object? What
is the weight?
m = ΣF / a = 7.5 kg
Wt = m g = - 73.575 N
12. A 120 N box slides on the floor. If the coefficient of kinetic friction is 0.22, find the
kinetic friction force.
Fk = μk FN = 26.4 N
D. Chapter 5: Work and Energy
1. Two students with the same mass climb a hill. A walks straight up and B takes a zigzag path. Which does more work? Which uses more power?
Work: Same for both
Power: A use more (less time)
2. Kinetic energy is energy due to _______motion_______.
Potential energy is energy due to ________position________________.
Mechanical energy is _____sum of KE + PE________________.
3. If the mass of an object triples, what happens to its KE? If the speed of an object
triples, what happens to its KE?
Mass triples: KE triples
Speed triples: KE is 9 times greater
4. To lift an object straight up, the force is equal and opposite to the ___weight__.
5. Is work a vector or scalar? Is energy a vector or scalar?
Work & Energy are both scalars
W = KE
MEi = MEf
PEg = mgh
W = F d cos
ME = KE + PEtot
6. How much work is done lifting a 20 kg box straight up 1.5 m?
F = Wt = 196.2 N
W = F d cos θ
W = 196.2 N (1.5 m) (cos 0°)
W = 294.3 J
7. How much work is done carrying a 20 kg object 10 m?
W = 0 J (F and d are , cos 90 = 0)
8. Find the KE of a 1200 kg car moving at 15 m/s.
KE = ½ m v2 = 135,000 J
P = W /t
KE = 1/2 m v2
9. Find the PE of a 45 kg boulder on top of a 30 m high cliff.
PEg = mgh = 13,243.5 J
10. A 1300 kg car slows from 25 m/s to 16 m/s. How much work was done on the car?
W = KE = ½ mvf2 – ½ mvi2 = 166,400 – 406,250 J = - 239,850 J
11. 5000 J of work is done on a car in 45 s. What is the power?
P = W / Δt = 111.11 w
E. Chapter 6: Momentum and Collisions
1. Identify the type of collision.
(A) objects stick together after the collision perfectly inelastic
(B) KE is conserved elastic
(C) KE is not conserved and objects have different Vf inelastic
2. What is the unit for momentum in the MKS system?
3. Is momentum a vector or scalar? vector
F t = p
mAvAi + mBvBi = mAvAf + mBvBf
F t = mvf - mvi
mAvAi + mBvBi = (mA + mB) vf
4. Find the momentum of a 3000 kg truck moving at 10 m/s.
30,000
5. A 0.15 kg baseball moving at +20 m/s is hit and now moves at –15 m/s. What was the
impulse delivered to the ball?
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