Revision Year 9 KS3 Science - Physics

What determines whether an object will float or sink in water?

• An object floats if it is made of plastic.

• An object floats if its density is less than that of water; it sinks if its density is greater.

• An object floats if it is lighter than air.

• An object sinks if it is larger than the water surface.

Explain the difference between heat and temperature.

• Heat is a measure of how hot something is.

• Heat is energy transfer; temperature is a measure of thermal energy.

• Temperature is the total energy in an object.

• Heat is the same as temperature.

What does it mean that energy is conserved?

• Energy can be created or destroyed in a closed system.

• Energy conservation means energy can change forms but not disappear.

• Energy is conserved when the total energy in a closed system remains constant.

• Energy is only conserved in open systems with external forces.

Describe the process of heat dissipation.

• Heat dissipation is the absorption of heat energy by a system.

• Heat dissipation occurs only through conduction.

• Heat dissipation is the process of generating heat within a system.

• Heat dissipation is the release of heat energy from a system to its surroundings through conduction, convection, and radiation.

How does thermal energy transfer from hot to cold?

• Thermal energy transfers only through chemical reactions.

• Cold objects absorb thermal energy without any transfer.

• Thermal energy only moves through conduction.

• Thermal energy transfers from hot to cold through conduction, convection, and radiation.

What are the three methods of thermal transfer?

• Conduction, convection, radiation

• Evaporation, condensation, sublimation

• Filtration, distillation, extraction

• Absorption, reflection, diffusion

Explain how cooling occurs through evaporation.

• Cooling occurs through evaporation as liquid molecules absorb heat and escape into the air, reducing the temperature of the remaining liquid.

• Cooling occurs through condensation as vapor molecules release heat into the air.

• Cooling occurs through conduction as heat is transferred from the liquid to a solid surface.

• Cooling occurs through radiation as liquid emits heat energy into the surrounding environment.

What is the relationship between amplitude and loudness in sound waves?

• Higher amplitude corresponds to greater loudness in sound waves.

• Higher amplitude leads to lower frequency in sound waves.

• Loudness is independent of amplitude in sound waves.

• Greater amplitude results in softer sounds.

How does frequency relate to the pitch of a sound?

• Pitch is determined solely by volume.

• Frequency is directly related to pitch; higher frequency means higher pitch.

• Lower frequency results in higher pitch.

• Frequency has no effect on pitch.

What happens to sound waves when they interact?

• Sound waves do not interact with each other.

• Sound waves can only travel in a straight line.

• Sound waves can reflect, refract, diffract, and interfere when they interact.

• Sound waves are only absorbed by materials.