Physics 8th: Understanding Forces and Motion

What is the difference between mass and weight?

• Weight is a measure of matter; mass is the force of gravity on that weight.

• Mass is a measure of matter; weight is the force of gravity on that mass.

• Mass and weight are the same and can be used interchangeably.

• Mass is the weight of an object; weight is its mass in kilograms.

Define balanced forces and give an example.

• Balanced forces are equal in size and opposite in direction, like a book on a table.

• Balanced forces are unequal in size and direction, like a car accelerating.

• Balanced forces are only present when an object is in motion, like a runner on a track.

• Balanced forces cause an object to move in one direction, like a ball rolling downhill.

What happens to an object when unbalanced forces act on it?

• The object experiences no change in motion.

• The object moves in a circular path at constant speed.

• The object remains at rest regardless of the forces.

• The object accelerates in the direction of the net force.

How does gravity affect weight?

• Gravity only affects the shape of objects.

• Gravity affects weight by determining the gravitational force acting on an object, making weight dependent on the strength of gravity.

• Weight is constant regardless of gravity.

• Gravity has no effect on weight.

If two forces of 10 N act in opposite directions, what is the net force?

• 0 N

• 10 N

• 20 N

• 5 N

What is the unit of measurement for mass?

• kilogram (kg)

• liter (L)

• meter (m)

• joule (J)

Explain how friction is a force that can be balanced or unbalanced.

• Friction is a type of energy that cannot oppose any force.

• Friction can be balanced when it opposes an equal force, and unbalanced when it exceeds the opposing force.

• Friction only acts in one direction and cannot be balanced.

• Friction is always unbalanced regardless of the forces involved.

What is the formula to calculate weight?

• Weight = Mass - gravitational acceleration

• Weight = Mass + gravitational acceleration

• Weight = Mass ÷ gravitational acceleration

• Weight = Mass × gravitational acceleration

If mass of an object is 66kg, calculate it's mass on the Earth.

• 630N

• 67N

• 660 kg

• 660 N

Give an example of a situation with unbalanced forces in everyday life.

• A car moving at a constant speed on a highway.

• A person standing still in a room.

• A book resting on a table.

• A person pushing a shopping cart.