Question

A mass 40kg is kept on a rough surface as shown. A person tries to pull this mass by attaching a uniform string
of mass 6 kg. The mass 40 kg is about to move when the person pulls the top end of string at an angle 370 with
horizontal while tangent at lower end of string is horizontal. If coefficient of friction between mass and ground is
N\10
find N.
​

Answer 1

Answer:

Answer

Correct option is

B

1m/s

2

Since P is the force which is just enough to start the motion of the body,

P=μ

s

N=μ

s

mg

When the body moves under this force, the net force on body is given by

F=ma=P−f

⟹ma=μ

s

mg−μ

k

N

=m(μ

s

−μ

k

)g

⟹a=(μ

s

−μ

k

)g

=(0.5−0.4)(10)m/s

2

⟹a=1m/s

2