Question

a constant force acting on a body of mass 3kg changes its speed from 2 meter per second square to 12 meter per second in 20 seconds. the direction of the motion of the body remains unchanged. find the magnitude of the force

Answer 1

Let us consider,
| u |= 2 m/s [not m/s^2, that ACCELERATION, and speed is VELOCITY]
| v |= 12 m/s
t= 20 s

As the direction of motion hasn’t changed,
Acceleration = (v - u)/t = (12-2)/20 = 1/2 m/s^2
Force = Mass * Acceleration
=> Force = 3 kg * 1/2 m/s^2 =
= 1.5 kg m/s^2