Newton's Laws of Motion — Homi Bhabha Exam Physics MCQs with Solutions
Free Homi Bhabha Exam Physics Newton's Laws of Motion MCQs with step-by-step solutions (6 questions). Part of Laws of Motion & Force. Practise online on Prepizo — no login needed.
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Questions with solutions
Q1 — Newton's Laws of Motion · medium · numerical
A force acts on a body of mass 5 kg producing an acceleration of 3 m/s². The magnitude of the force is:
A. 1.67 N
B. 8 N
C. 15 N ✓ Correct
D. 45 N
Solution: By Newton's second law $F = ma = 5 \times 3 = 15$ N.
Q2 — Newton's Laws of Motion · medium · theory
When a moving bus stops suddenly, a standing passenger lurches forward. This is best explained by:
A. Newton's first law (inertia of motion) ✓ Correct
B. Newton's third law
C. the law of conservation of momentum
D. Newton's second law
Solution: The lower body stops with the bus while the upper body tends to continue moving forward due to inertia of motion.
Q3 — Newton's Laws of Motion · hard · theory
Newton's second law of motion states that the net force on a body equals:
A. the rate of change of its momentum ✓ Correct
B. the product of its mass and velocity
C. its change in momentum
D. its mass times its speed
Solution: $F = \dfrac{\Delta p}{\Delta t}$; for constant mass this reduces to $F = ma$.
Q4 — Newton's Laws of Motion · hard · numerical
A force of 10 N acts to the right and a force of 4 N acts to the left on a 2 kg body. Its acceleration is:
A. 7 m/s² to the right
B. 3 m/s² to the right ✓ Correct
C. 5 m/s² to the right
D. 2 m/s² to the left
Solution: Net force $= 10 - 4 = 6$ N; $a = \dfrac{F}{m} = \dfrac{6}{2} = 3$ m/s² in the direction of the larger force.
Q5 — Newton's Laws of Motion · medium · theory
Assertion (A): A body in uniform motion continues to move uniformly unless an external force acts on it. Reason (R): This is a statement of Newton's first law (law of inertia).
A. Both A and R are true but R is NOT the correct explanation of A
B. A is false but R is true
C. A is true but R is false
D. Both A and R are true and R is the correct explanation of A ✓ Correct
Solution: A is exactly the content of the first law, which R names — so R correctly explains A.
Q6 — Newton's Laws of Motion · medium · numerical
A body of mass 4 kg experiences a net force of 20 N. Its acceleration is:
A. 80 m/s²
B. 5 m/s² ✓ Correct
C. 0.2 m/s²
D. 16 m/s²
Solution: $a = \dfrac{F}{m} = \dfrac{20}{4} = 5$ m/s².