FORCES (1)

Which statement about the mass and the weight of an object is correct?

• They are both affected by changes in the acceleration of free fall.

• They are both forces.

• They have different units.

• Weight is calculated by dividing mass by the acceleration of free fall.

An object decelerates from 25.0 m / s to 5.0 m / s in a time of 4.0 s.

It has a mass of 50 kg.

What is the resultant force on the object?

• 0.63 N

• 10 N

• 250 N

• 4000 N

A helium balloon is tied to a top-pan balance. A metal block of mass 100 g is placed on the balance. The reading on the balance is 91 g.

Which statement can be deduced from this experiment?

• The balloon exerts a downward force of 0.09 N on the top-pan balance.

• The helium has a mass of –9 g.

• The helium has a mass of +9 g.

• The resultant downward force on the top-pan balance is 0.91 N.

A box of mass 2.0 kg is pulled across the floor by a force of 6.0 N.

The frictional force acting on the box is 1.0 N.

What is the acceleration of the box?

• 0.40 m/s²

• 2.5 m/s²

• 3.0 m/s²

• 3.5 m/s²

A spring is stretched by hanging a piece of metal from it.

Which name is given to the force that stretches the spring?

• friction

• mass

• pressure

• weight

A body of mass m has a weight W in a location where the gravitational field strength is g.

Which statement about these quantities is correct?

• m and W are both forces.

• m and W are both vector quantities.

• m and W are related by the equation (W/m) = g

• m and W have the same unit

Each diagram shows a metal plate with four parallel forces acting on it. These are the only forces acting on the plates.

In which diagram is the plate in equilibrium?

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