Forces & their Interactions Practice Questions

Complete the table by writing scalar or vector for each quantity.

Explain why force is a vector quantity.

A vector quantity can be represented by an arrow drawn on a diagram.

State what the length of the arrow represents.

Here is a list of forces.

air resistance electrostatic force gravitational force tension

Give the two non-contact forces from the list.

The magnet and the paperclip interact.

Describe the forces produced by this interaction.

State one difference between the mass of the suitcase and the weight of the suitcase.

Calculate the weight of the suitcase.

Weight = .................... N

A second suitcase has a weight that is twice the weight of the first suitcase.

Give the mass of the second suitcase.

Name the force labelled X in Figure 1.

Determine the magnitude of the resultant horizontal force on the crate.

Resultant horizontal force = .................... N

Explain, using the information in Figure 1, why the crate is in equilibrium.

What is meant by the 'centre of mass' of an object?

A uniform rectangular metal sheet is cut from a larger sheet.

State where the centre of mass of the rectangular sheet is.

Describe how the shop assistant should use the newtonmeter to measure the weight of the bag of potatoes accurately.

What is meant by the 'resultant force' on an object?

Calculate the magnitude of the resultant force on the narrowboat and give its direction.

Resultant force = .................... N

Direction = ....................

Calculate the gravitational field strength on Mars.

Give the unit.

Gravitational field strength = .................... unit ....................

The rock sample is later brought back to Earth, where the gravitational field strength is 9.8 N/kg.

State and explain what happens to the mass of the rock sample and to the weight of the rock sample.

In the space below, draw a free body diagram for the falling ball.

Label each force with its name and its magnitude.

Determine the magnitude and direction of the resultant force on the ball.

Resultant force = .................... N

Direction = ....................

A student says that the resultant force on the sled is 280 N.

Explain why the student is wrong.

Determine the magnitude and direction of the resultant force on the sled by drawing a vector diagram.

Magnitude of resultant force = .................... N

Direction = .................... degrees from the 160 N force

Determine the horizontal component and the vertical component of the 50 N force by drawing a scale vector diagram.

Horizontal component = .................... N

Vertical component = .................... N

Explain what is meant by saying that the two components have the same effect as the single 50 N force.

The wagon stays on the path and the vertical forces on it are balanced.

Calculate the normal contact force from the path on the wagon.

Normal contact force = .................... N