Learn › NEET · Physics › Laws of Motion
Laws of Motion — NEET Physics MCQs with Solutions
Free NEET Physics Laws of Motion MCQs with step-by-step solutions covering Introduction to Force, Inertia, Newtons 3 Laws. Practise online on Prepizo — no login needed.
▶ Practise Laws of Motion online (free)
Subtopics
Sample questions with solutions
Q1 — Introduction to Force · easy · numerical
A body accelerates at $3$ m/s² under a force of $12$ N. Its mass is
A. $9$ kg
B. $4$ kg ✓ Correct
C. $0.25$ kg
D. $36$ kg
Solution: $m = F/a = 12/3 = 4$ kg.
Q2 — Introduction to Force · easy · numerical
The weight of a body of mass $10$ kg (g = 10 m/s²) is
A. $1$ N
B. $1000$ N
C. $10$ N
D. $100$ N ✓ Correct
Solution: $W = mg = 10 \times 10 = 100$ N.
Q3 — Introduction to Force · easy · numerical
A body has a weight of $50$ N. Its mass (g = 10 m/s²) is
A. $0.5$ kg
B. $50$ kg
C. $5$ kg ✓ Correct
D. $500$ kg
Solution: $m = W/g = 50/10 = 5$ kg.
Q4 — Introduction to Force · easy · numerical
Two collinear forces $5$ N and $3$ N act in the SAME direction. The net force is
A. $15$ N
B. $8$ N ✓ Correct
C. $4$ N
D. $2$ N
Solution: Same direction, so they add: $5 + 3 = 8$ N.
Q5 — Introduction to Force · easy · numerical
Two collinear forces $10$ N and $4$ N act in OPPOSITE directions. The net force is
A. $14$ N
B. $40$ N
C. $6$ N ✓ Correct
D. $2.5$ N
Solution: Opposite directions subtract: $10 - 4 = 6$ N.
Q6 — Introduction to Force · easy · numerical
The force needed to accelerate a $1000$ kg car at $2$ m/s² is
A. $2000$ N ✓ Correct
B. $2$ N
C. $500$ N
D. $1002$ N
Solution: $F = ma = 1000 \times 2 = 2000$ N.
Q7 — Introduction to Force · easy · numerical
The weight of a $10$ kg object on the Moon (g = 1.6 m/s²) is
A. $16$ N ✓ Correct
B. $6.25$ N
C. $1.6$ N
D. $100$ N
Solution: $W = mg = 10 \times 1.6 = 16$ N.
Q8 — Introduction to Force · easy · numerical
A spring of stiffness $200$ N/m is stretched by $0.1$ m. The force in the spring is
A. $0.5$ N
B. $20$ N ✓ Correct
C. $200.1$ N
D. $2000$ N
Solution: $F = kx = 200 \times 0.1 = 20$ N.
Q9 — Introduction to Force · easy · numerical
A force of $5$ kgf (g = 10 m/s²) expressed in newtons is
A. $500$ N
B. $0.5$ N
C. $50$ N ✓ Correct
D. $5$ N
Solution: $1$ kgf $= g$ N $= 10$ N, so $5$ kgf $= 50$ N.
Q10 — Introduction to Force · easy · theory
On a body, $10$ N acts right, and $3$ N and $2$ N act left. The net force is
A. $15$ N
B. $5$ N to the left
C. $9$ N
D. $5$ N to the right ✓ Correct
Solution: Net $= 10 - (3 + 2) = 5$ N to the right.
Q11 — Introduction to Force · easy · numerical
An $8$ kg body under a net force of $40$ N accelerates at
A. $0.2$ m/s²
B. $48$ m/s²
C. $320$ m/s²
D. $5$ m/s² ✓ Correct
Solution: $a = 40/8 = 5$ m/s².
Q12 — Introduction to Force · easy · numerical
A vertical string holds a $3$ kg mass in equilibrium. The tension (g = 10 m/s²) is
A. $30$ N ✓ Correct
B. $3$ N
C. Zero
D. $300$ N
Solution: Tension balances weight: $T = mg = 30$ N.
Q13 — Introduction to Force · easy · numerical
A body of mass $5$ kg has weight (g = 9.8 m/s²) approximately
A. $14.8$ N
B. $0.5$ N
C. $5$ N
D. $49$ N ✓ Correct
Solution: $W = 5 \times 9.8 = 49$ N.
Q14 — Introduction to Force · easy · numerical
A body weighs $200$ N. Its mass (g = 10 m/s²) is
A. $2$ kg
B. $2000$ kg
C. $200$ kg
D. $20$ kg ✓ Correct
Solution: $m = 200/10 = 20$ kg.
Q15 — Introduction to Force · easy · numerical
Two forces of $8$ N and $6$ N act at $90°$. The resultant makes with the $8$ N force an angle $\theta$ where $\tan\theta =$
A. $0.75$ ✓ Correct
B. $0.5$
C. $1.33$
D. $1$
Solution: $\tan\theta = \frac{6}{8} = 0.75$ (resultant is $10$ N).
Q16 — Introduction to Force · easy · numerical
A $50$ kg person stands in a stationary lift. The normal force on the person (g = 10 m/s²) is
A. $5000$ N
B. Zero
C. $50$ N
D. $500$ N ✓ Correct
Solution: Lift stationary: $N = mg = 50 \times 10 = 500$ N.
Q17 — Inertia · easy · numerical
Momentum, the measure of inertia of motion, of a $2$ kg body moving at $5$ m/s is
A. $10$ kg·m/s ✓ Correct
B. $7$ kg·m/s
C. $0.4$ kg·m/s
D. $2.5$ kg·m/s
Solution: $p = mv = 2 \times 5 = 10$ kg·m/s.
Q18 — Inertia · easy · numerical
The momentum of a $0.5$ kg ball moving at $20$ m/s is
A. $10$ kg·m/s ✓ Correct
B. $20.5$ kg·m/s
C. $0.025$ kg·m/s
D. $40$ kg·m/s
Solution: $p = 0.5 \times 20 = 10$ kg·m/s.
Q19 — Inertia · easy · theory
Which body has GREATER inertia: a $2$ kg or a $5$ kg body?
A. Cannot say
B. Both equal
C. The $2$ kg body
D. The $5$ kg body ✓ Correct
Solution: Inertia is measured by mass; the $5$ kg body has more mass, hence more inertia.
Q20 — Inertia · easy · numerical
A body has momentum $30$ kg·m/s and mass $3$ kg. Its velocity is
A. $27$ m/s
B. $10$ m/s ✓ Correct
C. $0.1$ m/s
D. $90$ m/s
Solution: $v = p/m = 30/3 = 10$ m/s.
Q21 — Inertia · easy · numerical
A body has momentum $40$ kg·m/s at a velocity of $8$ m/s. Its mass is
A. $0.2$ kg
B. $320$ kg
C. $5$ kg ✓ Correct
D. $48$ kg
Solution: $m = p/v = 40/8 = 5$ kg.
Q22 — Inertia · easy · numerical
A body moves at a constant velocity of $10$ m/s with no external force. By the law of inertia, its velocity after $5$ s is
A. $10$ m/s ✓ Correct
B. $50$ m/s
C. Zero
D. $2$ m/s
Solution: With no net force, Newton's first law keeps the velocity unchanged at $10$ m/s.
Q23 — Inertia · easy · numerical
The momentum of a $1000$ kg car moving at $20$ m/s is
A. $50$ kg·m/s
B. $2000$ kg·m/s
C. $20000$ kg·m/s ✓ Correct
D. $1020$ kg·m/s
Solution: $p = 1000 \times 20 = 20000$ kg·m/s.
Q24 — Inertia · easy · numerical
The momentum of a $0.2$ kg ball moving at $15$ m/s is
A. $30$ kg·m/s
B. $75$ kg·m/s
C. $3$ kg·m/s ✓ Correct
D. $0.013$ kg·m/s
Solution: $p = 0.2 \times 15 = 3$ kg·m/s.
Q25 — Inertia · easy · numerical
A body of mass $2$ kg has momentum $8$ kg·m/s. Its velocity is
A. $0.25$ m/s
B. $16$ m/s
C. $4$ m/s ✓ Correct
D. $10$ m/s
Solution: $v = 8/2 = 4$ m/s.
Q26 — Inertia · easy · theory
If the velocity of a $2$ kg body increases from $5$ m/s to $10$ m/s, its momentum changes from
A. $10$ to $20$ kg·m/s ✓ Correct
B. $5$ to $10$ kg·m/s
C. $2$ to $4$ kg·m/s
D. $20$ to $10$ kg·m/s
Solution: $p_1 = 10$, $p_2 = 20$ kg·m/s — momentum doubles as velocity doubles.
Q27 — Inertia · easy · numerical
A cricket ball of mass $0.15$ kg moves at $20$ m/s. Its momentum is
A. $3$ kg·m/s ✓ Correct
B. $133$ kg·m/s
C. $20.15$ kg·m/s
D. $0.0075$ kg·m/s
Solution: $p = 0.15 \times 20 = 3$ kg·m/s.
Q28 — Inertia · easy · numerical
Two bodies have equal momentum $12$ kg·m/s. One is $2$ kg moving at $6$ m/s; the other is $4$ kg. Its velocity is
A. $2$ m/s
B. $48$ m/s
C. $6$ m/s
D. $3$ m/s ✓ Correct
Solution: $v = p/m = 12/4 = 3$ m/s.
Q29 — Inertia · easy · theory
Which has greater inertia: a $10$ kg block or a $100$ g ball?
A. The $10$ kg block ✓ Correct
B. Both equal
C. The $100$ g ball
D. Depends on velocity
Solution: $10$ kg $= 100 \times 0.1$ kg, so the block has $100$ times more mass and inertia.
Q30 — Inertia · easy · numerical
A body of momentum $100$ kg·m/s has a mass of $20$ kg. Its velocity is
A. $5$ m/s ✓ Correct
B. $80$ m/s
C. $2000$ m/s
D. $0.2$ m/s
Solution: $v = 100/20 = 5$ m/s.