A small block of mass of lies on a fixed inclined plane which makes an angle with the horizontal. A horizontal force of 1 N acts on the block through its centre of mass as shown in the figure. The block remains stationar

Question

A small block of mass of $0.1 kg$ lies on a fixed inclined plane $P Q$ which makes an angle $θ$ with the horizontal. A horizontal force of 1 N acts on the block through its centre of mass as shown in the figure.

The block remains stationary if (take $g = 10 {m/s}^{2}$ ) [2012]

Smart Achievers · Accepted Answer

(1, 3)

The various forces acting on the block are as shown in the figure.

When $P Q$ , $\sin θ = \cos θ$

The block will remain stationary and the frictional force is zero.

When $θ > 45 °$ , $\sin θ > \cos θ$

Therefore a frictional force acts towards Q.

When $θ < 45 °$ , $\cos θ > \sin θ$ .

Therefore a frictional force acts towards P.

Solution

Q.
A small block of mass of $0.1 kg$ lies on a fixed inclined plane $P Q$ which makes an angle $θ$ with the horizontal. A horizontal force of 1 N acts on the block through its centre of mass as shown in the figure.

The block remains stationary if (take $g = 10 {m/s}^{2}$ ) [2012]

1 $θ = 45 °$

2 $θ > 45 °$ and a frictional force acts on the block towards P

3 $θ > 45 °$ and a frictional force acts on the block towards Q

4 $θ < 45 °$ and a frictional force acts on the block towards Q

Want Us to Email you About Special Offers & Updates?

Solution

Q. A small block of mass of 0.1 kg lies on a fixed inclined plane PQ which makes an angle θ with the horizontal. A horizontal force of 1 N acts on the block through its centre of mass as shown in the figure. The block remains stationary if (take g=10 m/s2) [2012]

1 θ=45°

2 θ>45° and a frictional force acts on the block towards P

3 θ>45° and a frictional force acts on the block towards Q