Question

A brick with a mass of 3 kg is set on an incline angled at 37°. The block accelerates down the incline at 3 m/s2. What is the magnitude of the frictional force acting on the brick?

Answer 1

Given,

The mass of the brick, m=3 kg

The angle of inclination, θ=37°

The acceleration of the brick, a=3 m/s²

The net force acting on the block is given by the difference between the horizontal component of the weight of the block and the frictional force acting on the brick.

Thus the net force acting on the block is given by,

`ma=mg\sin \theta-f`

Where g is the acceleration due to gravity and f is the frictional force acting on the brick.

On substituting the known values in the above equation,

`\begin{gathered} 3*3=3*9.8*\sin 37^(\circ)-f \\ f=3*9.8*\sin 37^(\circ)-3*3 \\ =8.69\text{ N} \end{gathered}`

Thus the magnitude of the frictional force acting on the brick is 8.69 N.