COMPREHENSIVE REVIEW OF KINEMATICS, DYNAMICS, ENERGY, AND
MOMENTUM WITH COMPLETE ANSWER EXPLANATIONS
1. A car starts from rest and accelerates uniformly at 4.0 m/s² for 6.0 s.
What is the final speed of the car?
A. 24 m/s
B. 10 m/s
C. 12 m/s
D. 36 m/s
Correct Answer: A
Rationale: Using the kinematic equation v = u + at, where u = 0, a = 4.0
m/s², and t = 6.0 s, v = 0 + (4.0)(6.0) = 24 m/s.
2. A runner travels 300 m north and then 400 m east. What is the
magnitude of the runner's displacement?
A. 700 m
B. 500 m
C. 100 m
D. 350 m
Correct Answer: B
Rationale: Displacement is the straight-line distance from start to finish.
Using the Pythagorean theorem, sqrt(300² + 400²) = sqrt(90000 +
160000) = sqrt(250000) = 500 m.
3. A ball is thrown vertically upward with an initial speed of 30 m/s.
Approximately how long does it take to reach its highest point? (g =
9.8 m/s²)
,A. 1.53 s
B. 4.08 s
C. 3.06 s
D. 2.04 s
Correct Answer: C
Rationale: At the highest point, the final velocity is 0 m/s. Using v = u +
at, 0 = 30 - 9.8t, so t = .8 = 3.06 s.
4. A vehicle moving at 15 m/s increases its speed uniformly to 35 m/s
over 5.0 s. What is the vehicle's average acceleration?
A. 10 m/s²
B. 4.0 m/s²
C. 7.0 m/s²
D. 2.0 m/s²
Correct Answer: B
Rationale: Average acceleration is the change in velocity divided by the
time interval. a = (35 - 15) / 5.0 = .0 = 4.0 m/s².
5. Which of Newton's laws explains why a passenger continues to
move forward when a car suddenly stops?
A. Second law
B. First law
C. Third law
D. Law of universal gravitation
Correct Answer: B
Rationale: Newton's first law, also known as the law of inertia, states
that an object in motion stays in motion unless acted upon by an
external force.
,6. A 10 kg block is pushed with a horizontal force of 50 N on a
frictionless surface. What is the acceleration of the block?
A. 0.2 m/s²
B. 500 m/s²
C. 5 m/s²
D. 10 m/s²
Correct Answer: C
Rationale: According to Newton's second law, F = ma. Therefore, a = F /
m = 50 N / 10 kg = 5 m/s².
7. What is the weight of a 15 kg object on Earth? (g = 9.8 m/s²)
A. 15 N
B. 1.53 N
C. 9.8 N
D. 147 N
Correct Answer: D
Rationale: Weight is the force of gravity on an object, calculated as W =
mg. W = 15 kg * 9.8 m/s² = 147 N.
8. A 2 kg ball is moving at 6 m/s. What is its kinetic energy?
A. 36 J
B. 12 J
C. 72 J
D. 6 J
Correct Answer: A
Rationale: Kinetic energy is calculated as KE = 0.5 * m * v². KE = 0.5 * 2
kg * (6 m/s)² = 36 J.
9. A force of 20 N acts over a distance of 3 m in the direction of
motion. How much work is done?
, A. 6.67 J
B. 60 J
C. 23 J
D. 0.15 J
Correct Answer: B
Rationale: Work is defined as force multiplied by displacement. W = F *
d = 20 N * 3 m = 60 J.
10. A 5 kg block slides down a frictionless incline of 30°. What is its
acceleration? (g = 9.8 m/s²)
A. 4.9 m/s²
B. 9.8 m/s²
C. 8.5 m/s²
D. 2.5 m/s²
Correct Answer: A
Rationale: On a frictionless incline, acceleration is a = g * sin(θ). a = 9.8
* sin(30°) = 9.8 * 0.5 = 4.9 m/s².
11. A 1000 kg car rounds a curve of radius 50 m at a constant speed of
10 m/s. What is the centripetal force required?
A. 200 N
B. 5000 N
C. 2000 N
D. 1000 N
Correct Answer: C
Rationale: Centripetal force is Fc = m * v² / r. Fc = 1000 * 10² / 50 =
= 2000 N.
12. Two objects collide and stick together after impact. This type of
collision is best described as: