G9 IGCSE Forces Quiz

A car moves along a level road.

The diagram shows all of the horizontal forces acting on the car.

Which statement is correct?

• The car is slowing down.

• The car is speeding up.

• The car is moving at a constant speed.

• The car is moving backwards.

Which force and distance produce the smallest moment about a pivot?

• a 6.0 N force at a perpendicular distance of 4.0m from the pivot

• a 7.0 N force at a perpendicular distance of 6.0 m from the pivot.

• a 10 N force at a perpendicular distance of 4.0 m from the pivot

• a 12 N force at a perpendicular distance of 3.0 m from the pivot.

An object is suspended from a spring balance on the Earth. The same object is suspended from the same spring balance on another planet.

Which statement explains the difference between the two readings?

• Both the mass and the weight of the object are greater on the other planet.

• The mass of the object is greater on the other planet than on Earth, but the weight is unchanged.

• The spring stretches more easily when on the other planet.

• The weight of the object is greater on the other planet than on Earth, but the mass is unchanged.

A resultant force of 4.0N acts on an object of mass 0.50 kg for 3.0 seconds.

What is the change in velocity caused by this force?

• 4.0 m / s

• 6.0 m / s

• 12 m / s

• 24 m / s

Which quantities are both vectors?

• acceleration and force

• acceleration and pressure

• density and force

• density and pressure

A moving ball with a momentum of 25 kg m /s collides head-on with a wall.

It rebounds from the wall with the same speed but in the opposite direction. The time of collision is 50 ms.

What is the average force exerted on the wall by the ball during the collision?

• 0.50 N

• 1.00 N

• 500 N

• 1000 N

The diagram shows a tug-of-war between team X and team Y. The arrows show the forces exerted by the teams on the rope.

What is the size of the resultant force on the rope and in which direction does the resultant force act?

• size of resultant force = 75 N; direction of resultant force = to the left

• size of resultant force = 75 N; direction of resultant force = to the right.

• size of resultant force = 725 N; direction of resultant force = to the left

• size of resultant force = 725 N; direction of resultant force = to the right.

A bag of flour has a mass of 540 g. The acceleration of free fall is 10 m /s².

What is the weight of the bag of flour?

• 5.4 N

• 54 N

• 540 N

• 5400 N

Which property of an object cannot be changed by a force?

• mass

• motion

• shape

• size

An unstretched spring obeys Hooke’s law and has a length of 10 cm. A load with a mass of 2.0 kg is hung from it, and its length becomes 14 cm.

The load is now increased to 6.0 kg, and the new length of the spring is Y. The limit of proportionality is not reached.

What is Y?

• 22 cm

• 26 cm

• 30 cm

• 42 cm