<u>Answer;</u>
<em>D. The object’s weight changes, but its mass stays the same.</em>
<u>Explanation;</u>
- Mass is the amount of matter in a object, which is measured in kilograms. Mass of an object is measured using a beam balance. It is important to note that the mass of an object or a body remains constant, and does not vary from one place to another. For instance the mass of a person on the moon will be the same as when the person is on the earth surface.
- Weight on the other hand is the measurement of gravitational pull of an object. weight is measured using a spring balance and measured in Newtons. Weight varies from one place to another depending on the gravitational pull of a given surface.
Answer:
c
Explanation:
c. the ability to do work or to produce heat
An element would be the type of substance that only contains one kind of matter.
Steel materials produce less vibrations whilst less dense and more malleable parts produce more vibrations, e.g. the wooden part of the coaster itself.
Efficiency of heat engine is determined by the ratio of difference in temperature of cold from hot reservoir to the temperature of hot reservoir over temperature of hot reservoir.
Answer: Option A
<u>Explanation:</u>
Efficiency is defined as the output from the input. So it is the ratio of energy output to the energy input. In case of temperature, it is the change in temperature from hot reservoir to cold reservoir with the overall hot reservoir temperature.

Thus, option A is the most suitable as the heat will be transferred from high temperature to low temperature. So the hot reservoir will be releasing the energy. So the conversion of hot reservoir temperature to cool reservoir temperature is defined as the efficiency. Thus, option A is the most suitable.