A block of mass $1.5 \mathrm{kg}$ is at rest on a rough surface which is inclined at $20°$ to the horizontal as shown.

Use your answer to part $b$ to determine the force of friction that acts on the block.

A block of mass $1.5 \mathrm{kg}$ is at rest on a rough surface which is inclined at $20°$ to the horizontal as shown.

(d) If the angle of the surface is actually measured as $19°$ and $21°$ determine the absolute uncertainty in this angle and the uncertainty this produces in the value of the component of the weight that acts down the slope.

A block of mass $1.5 \mathrm{kg}$ is at rest on a rough surface which is inclined at $20°$ to the horizontal as shown.

Determine the normal contact force between the block and the surface

This free-body diagram shows three forces that act on a stone hanging at rest from two strings.

Calculate the horizontal component of the tension in each string. State why these two components are equal in magnitude?

This free-body diagram shows three forces that act on a stone hanging at rest from two strings.

Calculate the vertical component of the tension in each string.

This free-body diagram shows three forces that act on a stone hanging at rest from two strings.

Use your answer to part $b$ to calculate the weight of the stone.

This free-body diagram shows three forces that act on a stone hanging at rest from two strings.

Draw a vector diagram of the forces on the stone. This should be a triangle of forces.

This free-body diagram shows three forces that act on a stone hanging at rest from two strings.

Use your diagram in part $d$ to calculate the weight of the stone.

The force $\mathrm{F}$ shown here has a moment of $40 \mathrm{Nm}$ about the pivot. Calculate the magnitude of the force $\mathrm{F}$.