First C.A Test (Second term)

Which of the following is a force?

• a) Temperature

• b) Speed

• c) Gravity

• d) Volume

Answer explanation

Gravity is a force that attracts objects towards each other.

What is the SI unit of force?

• a) Newton

• b) Joule

• c) Watt

• d) Pascal

Answer explanation

The SI unit of force is Newton. Newton is the correct choice because it is the unit used to measure force in the International System of Units (SI).

Which of the following is a contact force?

• a) Friction

• b) Magnetic force

• c) Electrostatic force

• d) Gravitational force

Answer explanation

Friction is a contact force that occurs when two surfaces rub against each other. It opposes the motion and is the correct choice in this question.

What is the formula to calculate force when a mass is accelerated?

• a) F = ma

• b) F = mv

• c) F = mgh

• d) F = pt

Answer explanation

The formula to calculate force when a mass is accelerated is F = ma. This formula states that force is equal to the mass of an object multiplied by its acceleration. Therefore, option a) F = ma is the correct choice.

Which of the following is an example of an elastic material?

• d) Glass

• c) Metal

• a) Rubber band

• b) Wood

Answer explanation

Rubber band is an example of an elastic material because it can stretch and return to its original shape.

What determines the strength of the gravitational force between two objects?

• a) Their masses and the distance between them

• b) Their colors

• c) Their speeds

• d) Their shapes

Answer explanation

The strength of the gravitational force between two objects is determined by their masses and the distance between them. This is the correct choice.

Maya, Henry, and James are trying to figure out how to demagnetize a magnet. What method should they use?

• a) Heating it

• b) Cooling it

• c) Bending it

• d) Painting it

Answer explanation

To demagnetize a magnet, heating it is the correct method. Heating disrupts the alignment of magnetic domains, reducing the magnetism. Cooling, bending, or painting the magnet won't demagnetize it.

What happens to the strength of the magnetic force when two magnets are moved farther apart?

• a) It increases

• b) It decreases

• c) It remains the same

• d) It becomes unpredictable

Answer explanation

When two magnets are moved farther apart, the strength of the magnetic force decreases. This is because the magnetic field weakens with distance.

What happens when you bring the north poles of two magnets close together?

• a) They attract each other

• b) They repel each other

• c) Nothing happens

• d) They spin around

Answer explanation

When the north poles of two magnets are brought close together, they repel each other. This is because like poles repel. Therefore, option b) is the correct choice.

When Elijah squeezes a stress ball and then releases it, what force causes it to regain its original shape?

• a) Tension

• b) Elastic force

• c) Gravity

• d) Friction

Answer explanation

When Elijah squeezes a stress ball and then releases it, the force that causes it to regain its original shape is the elastic force. This force is generated by the material of the stress ball, which has the ability to deform and then return to its original shape.