Question

You push a heavy box of mass 50 kg with a force of 150 N. The box was initially at rest and after 3 seconds, it has a speed of 6 m/s. If friction is the only other horizontal force on the box apart from the force you exert, find the magnitude of friction force in the direction of motion of the box

Answer 1

Answer : m = 50 kg
F = 150 N
u = 0
v = 6 m/s
t = 3 s
According to motion equation
v = u + a* t
6 = 0 + a* 3
6/3 = a
a = 2m/s
Net force = m* a
External force - friction force = 50* 2
150 - f = 100
So, f = 150 - 100
= 50 N