Question

A contract force act on an object of mass 10 kg for a time period of 4 sec it increase the velocity of the object from 2m/s to 8m/s find the magnitude of the applied force

Answer 1

As, F=ma
a=v-u/t
= 8-2/4
= 3/2m/s^2
Now, put the value of acceleration in formula of force
F=ma
=10*3/2
=5*3
=15N

Answer 2

mass=10 kg
acceleration = final velocity - initial velocity/ time
                     =8-2/4 = 6/4= 1.5 m/s 2
force = mass * acceleration
         = 10 * 1.5 = 15 newtons