Question

In order to gain a velocity of 12m/s, how long should a force of 30N be exerted on a body of mass 5 kg.​

Answer 1

Answer:

Time = 2 seconds

Explanation:

Required velocity to be gained = v = 12 m/s

Force applied = F = 30 N

Mass = m = 5 kg

According to Newton's 2nd law,

F = ma

We know that acceleration = a = v/t

F = mv/t

t = mv/F => t = 5×12/30 = 60/30 = 2s

Time t that the force 30 N must be applied so that the body of mass 5 kg gains a velocity of 12 m/s is 2s

Answer 2

Answer:

Answer is 2 seconds

Explanation:

Lets suppose  u = 0 (initial velocity)

v = 12 m/s (final velocity)

F = 30N

mass = 5kg

Acceleration = Force/mass = 30/5 = 6m/s²

First equation of motion is  v = u + at

t = (v - u)/a

t = (12-0)/6 = 2s

Therefore, time = 2s