Week 4 - Newton's Law Revision Quiz

If you lean against a brick wall, the wall:

• does not push back

• pushes back with a smaller force

• pushes back with an equal force

• pushes back with a greater force

If all the forces acting on an object are balanced then the net force acting on it is zero.

• True

• False

If an object is not moving then there must be no forces acting on it.

• True

• False

An elevator is rising up a vertical shaft in a skyscraper. Between the 12th and 20th floors it travels at a constant speed. During this time period:

• the forces acting on it are balanced so the net force is zero

• the only unbalanced force acting on it is air resistance

• there are no forces acting on it so the net force is zero

• the upward force is greater than the combined downward forces of gravity and air resistance, making it move upward

Friction and air resistance are forces that always:

• 
  

  act in the opposite direction to an object's motion, tending to slow it down

• balance out, having no effect on the net force

• cause objects to speed up

• pull objects down towards the centre of the Earth

The arrows on a free body diagram represent:

• the inertia of an object

• all of the forces acting on an object

• the motion of an object

• the net force on an object

A free body diagram can be used to help work out the net force acting on an object.

• True

• False

A jet ski shoots a jet of water out the back, which propels the jet ski forwards.

The force on the jet of water and the force on the jet ski are:

• equal in strength and act in opposite directions

• unequal in strength and act in the same direction

• equal in strength and act in the same direction

• unequal in strength and act in opposite directions

Select the word equation that sums up the relationship between force, mass and acceleration. 

• Force equals mass times acceleration

• Force equals mass minus acceleration

• Force equals mass divided by acceleration

• Force equals mass plus acceleration

The same sized force is applied to three balls of different mass.

Identify how the acceleration of the balls depends on their mass. 

• The higher the mass, the lower the acceleration

• The higher the mass, the higher the acceleration

• All three balls would have the same acceleration