Forces Vocabulary

What is a force?

• A force is a type of energy.

• A force is a form of matter.

• A force is a measurement of time.

• A force is a push or pull.

Answer explanation

The question asks about the definition of a force. The correct answer is 'A force is a push or pull.' This is because, in physics, a force refers to any interaction that, when unopposed, will change the motion of an object. Thus, a force is accurately described as a push or a pull, not a type of energy, form of matter, or a measurement of time.

What is an example of a non-contact force?

• Pushing a car.

• Gravity.

• Pulling a door.

• Lifting a box.

Answer explanation

The question asks for an example of a contact force. Contact forces require direct interaction between two objects, and the given options are pulling a rope, lifting a book, kicking a ball, and pushing a door. The correct choice is pushing a door because pushing involves applying a force directly on the object, which is a characteristic of contact forces.

Give an example of a noncontact force.

• gravity

• tension

• friction

• magnetism

Answer explanation

Gravity and magnetism are examples of noncontact forces as they can exert a force without touching objects. Tension and friction, however, require contact to exert force. Thus, 'gravity' and 'magnetism' are correct.

What is the difference between contact and noncontact forces?

• Contact forces require physical contact between objects, while noncontact forces act at a distance without physical contact.

• Contact forces are stronger than noncontact forces, while noncontact forces are weaker and have less impact.

• Contact forces only occur between solid objects, while noncontact forces can occur between any type of objects.

• Contact forces act at a distance without physical contact, while noncontact forces require physical contact between objects.

Answer explanation

The question asks about the difference between contact and noncontact forces. The correct answer is that contact forces require physical contact between objects, in contrast to noncontact forces, which act at a distance without needing physical contact. This highlights the main distinction between these two types of forces.

What is the unit of force?

• Kilogram (kg)

• Meter (m)

• Second (s)

• Newton (N)

Answer explanation

The question asks for the unit of force. In the options given, Kilogram, Meter, and Second are units of mass, length, and time respectively. Newton, however, is the standard unit of force in the International System of Units (SI). Therefore, the correct choice is Newton (N).

What is the net force?

• The net force is the force exerted by an object on another object.

• The net force is the force required to keep an object in motion.

• The net force is the force exerted by an object on itself.

• The net force is the vector sum of all the individual forces acting on an object.

What is friction?

• Force that causes motion

• Force that opposes motion

• Force that attracts objects

• Force that increases speed

What is gravity?

• Gravity is a force that repels objects away from each other.

• Gravity is a force that attracts objects towards each other.

• Gravity is a force that only affects large objects.

• Gravity is a force that only exists on Earth.

What is magnetism?

• Magnetism is a force that only repels certain materials.

• Magnetism is a force that only attracts certain materials.

• Magnetism is a force that attracts or repels certain materials.

• Magnetism is a force that has no effect on materials.

What is air resistance?

• Force that attracts objects towards each other.

• Force that opposes the motion of an object through the air

• Force that assists the motion of an object through the air.

• Force that causes objects to sink in water.