This answer of the strength and directions of the magnetic field is a
A billiard ball strikes another of the same mass at rest and stops, and the second ball then moves with the same velocity as the first ball would be an example of an elastic collision. This type of collision conserve both kinetic energy and momentum. The kinetic energy before they collide is equal after the collision.
Explanation:
- A thermometer does measure the temperature of a body and not the heat. It is known that temperature is a measure of average kinetic energy.
Therefore, the statement a thermometer measures the average kinetic energy of a substance is correct.
- Heat is a form of energy as it can make a colder substance become hot and it moves from one place to another. Thus, the statement heat is a form of energy is correct.
- Also, heat flows from hotter substance to colder substance. Hence, the statement heat flows from a colder substance to a hotter substance is correct.
- Convection is a property of fluids or gases which makes less denser (hot) material to rise and more denser (colder) material to sink.
Therefore, the statement convection occurs only in liquids and gases is correct.
- All substances radiate heat is an incorrect statement. For example, a thermos bottle does not radiate heat.
- Temperature of our body is about 98.4 degree celsius and hence we can conclude that the statement our body temperature is always equal to the temperature around us is incorrect.
True. If the amount displaced is more than the mass, it floats. If the amount is less than the mass, it will sink.