A force $F$ is applied at a distance $d$ from the hinge $H$ and an angle $x$ to the door.

What is the moment of force $F$ bout the point $H$ ?

The angle between two forces each of magnitude $5.0 \mathrm{N}$ is $120°$.

What is the magnitude of the resultant of these two forces ?

A ship is pulled at a constant speed by two small boats $\mathrm{A} \& \mathrm{B}$ as shown.

The engine of the ship does not produce any force.

The tension in each cable between $\mathrm{A}$ and $\mathrm{B}$ and the ship is $4000 \mathrm{N}$.

(Draw a free-body diagram showing the three horizontal forces acting on the ship.

A ship is pulled at a constant speed by two small boats $\mathrm{A} \& \mathrm{B}$ as shown.

The engine of the ship does not produce any force.

The tension in each cable between $\mathrm{A}$ and $\mathrm{B}$ and the ship is $4000 \mathrm{N}$.

Draw a vector diagram to scale showing these three forces and use your diagram to find the value of the drag force on the ship.

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.

Draw a free-body diagram showing the three forces acting 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.

Calculate 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.

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