Question

A box of 4 kg rests upon incline plane of the inclination of the brain to the horizontal is gradually increased it is found that when the slope of the plane is one in three in the box starts sliding down the plane given equal 9.8 M per second square
1. find the coefficient of friction between the box and the plane
2. what force applied to the box parallel to the plane will just make it Move off the plane

Answer 1

Take help from the diagram

Answer 2

Answer:

0.35;26.13N

Explanation:

Here, m=4kgsinθ=13

μ=?F=?

μ=tanθ=18–√=0.35

As the box is to move up the plane force of friction is down the plane

F=mgsinθ+f=mgsinθ+μmgcosθ

=mg(sinθ+μcosθ)

=4×9.8(13+0.358–√3)=26.13N