Question

9. A box is pushed for 5 s across the floor with a force of
130 N and the frictional force between the box and the
floor is 30 N. Determine (a) the net force acting on the
box, (b) acceleration of the box, if starting from rest it
is pushed 25 m in 5 s, (c) mass of the box, and (d) final
kinetic energy of the box.​

Answer 1

Answer:

We know frictional force f=μN where N=normal force=mg

Given sliding frictionμ=0.25

Thus, f=0.25×50×10=125N

Hence F

net

=F

app

−f=575−125=450N

Also we know ForceF=ma

a=

50

450

=9m/s

2