A 5 N force is defined when a mass of 10 kg is accelerated with
- (a)5.0 cm/s²
- (b)0.5 m/s²
- (c)0.5 cm/s²
- (d)5.0 m/s²
Correct — B, 0.5 m/s². By Newton's second law, force = mass × acceleration, so acceleration = force ÷ mass = 5 N ÷ 10 kg = 0.5 m/s². One newton is the force that gives a 1 kg mass an acceleration of 1 m/s², so 5 N on a 10 kg mass produces half that, 0.5 m/s².
- (a)5.0 cm/s² — Both the value and the unit are wrong; 0.5 m/s² equals 50 cm/s², not 5 cm/s².
- (c)0.5 cm/s² — The number 0.5 is right but the unit is not — the SI answer is 0.5 m/s², which is 100 times larger than 0.5 cm/s².
- (d)5.0 m/s² — This ignores the factor of 10 (the mass); it would be the acceleration only if the mass were 1 kg, not 10 kg.
Newton's second law states that the net force on a body equals its mass times its acceleration, F = m·a. Rearranged, the acceleration produced by a force is a = F/m — inversely proportional to the mass.
The wrong options bait you on units and on the arithmetic direction — dividing 5 by 10 (correct) rather than multiplying, and keeping SI units (m/s², not cm/s²).
- Newton's second law: F = m·a, so a = F/m.
- One newton (1 N) is defined as 1 kg·m/s².
- Here a = 5 N ÷ 10 kg = 0.5 m/s².
- 0.5 m/s² = 50 cm/s², so the correct unit matters for the answer.
Divide the force by the mass; keep SI units — the answer is 0.5 m/s².
- Multiplying force by mass instead of dividing.
- Leaving the answer in cm/s² when SI requires m/s².
A one-step F = ma calculation — find the acceleration from a given force and mass, watching the units.
No directly related past PYQ was found.
- practice — not a real PYQ
A force of 20 N acts on a 4 kg mass. Its acceleration is
- (a)80 m/s²
- (b)5 m/s²
- (c)0.2 m/s²
- (d)24 m/s²
Answer(b) 5 m/s² — a = F/m = 20 ÷ 4.
- practice — not a real PYQ
One newton is the force that gives a mass of 1 kg an acceleration of
- (a)1 cm/s²
- (b)10 m/s²
- (c)1 m/s²
- (d)9.8 m/s²
Answer(c) 1 m/s² — that is the definition of the newton (1 N = 1 kg·m/s²).