IGCSE Science Year 8 forces and light

What is the SI unit of force?

• Newton (N)

• Second (s)

• Meter (m)

• Kilogram (kg)

Explain the difference between contact and non-contact forces.

• Contact forces act on objects in space, while non-contact forces act on objects on Earth.

• Contact forces are stronger than non-contact forces.

• Contact forces involve magnets, while non-contact forces involve gravity.

• Contact forces require physical contact between objects, while non-contact forces can act over a distance without direct contact.

How does the force of gravity affect objects on Earth?

• Gravity on Earth causes objects to float in the air

• Gravity on Earth pulls objects towards the center of the planet, causing them to accelerate at a rate of 9.81 m/s^2.

• Gravity on Earth pushes objects away from the center of the planet

• Gravity on Earth has no effect on objects

Define the term 'refraction' in the context of light.

• Refraction is the bending of light as it passes from one medium to another due to a change in its speed.

• Refraction is the reflection of light off a surface

• Refraction is the emission of light from a source

• Refraction is the absorption of light by a medium

What is the difference between reflection and refraction?

• Reflection is the scattering of light, while refraction is the diffraction of light.

• Reflection is the bending of light, while refraction is the bouncing back of light.

• Reflection is the absorption of light, while refraction is the emission of light.

• Reflection is the bouncing back of light, while refraction is the bending of light.

Explain how a concave lens diverges light rays.

• A concave lens absorbs light rays.

• A concave lens has no effect on light rays.

• A concave lens converges light rays towards the principal axis.

• A concave lens diverges light rays by refracting them away from the principal axis.

What is the relationship between the angle of incidence and the angle of reflection?

• They are equal

• They are random

• They are perpendicular

• They are parallel

Describe how light travels through different mediums.

• Light travels through different mediums by creating magnetic fields

• Light travels through different mediums by changing color

• Light travels through different mediums by being absorbed, transmitted, reflected, or refracted depending on the properties of the medium.

• Light travels through different mediums by producing sound waves

What is the role of a prism in the dispersion of light?

• To reflect light at the same angle

• To refract different wavelengths of light at different angles.

• To emit light of different colors

• To absorb light instead of refracting it

How does the color of an object affect the amount of light it absorbs?

• The color of an object has no impact on the amount of light it absorbs

• The color of an object affects the amount of light it absorbs by influencing which wavelengths of light are reflected and which are absorbed.

• Objects of different colors absorb light equally

• Light absorption is solely determined by the object's size, not color