Energy changes in a system

Question 2

What is the definition of energy in physics?

Answer 2

Energy is the capacity to do work or produce heat.

Question 3

True or False: Energy can be created or destroyed.

Answer 3

False: Energy cannot be created or destroyed, only transformed.

Question 4

What is kinetic energy?

Answer 4

Kinetic energy is the energy of an object due to its motion.

Question 5

Fill in the blank: The formula for kinetic energy is _____ = 1/2 mv².

Answer 5

KE

Question 6

What is potential energy?

Answer 6

Potential energy is the stored energy of an object due to its position or state.

Question 7

Which type of potential energy is associated with an object’s height?

Answer 7

Gravitational potential energy.

Question 8

What is the formula for gravitational potential energy?

Answer 8

PE = mgh, where m is mass, g is acceleration due to gravity, and h is height.

Question 9

What is the law of conservation of energy?

Answer 9

The total energy in a closed system remains constant over time.

Question 10

Multiple Choice: Which of the following is NOT a form of energy? A) Thermal B) Chemical C) Gravity D) Kinetic

Answer 10

C) Gravity

Question 11

What is thermal energy?

Answer 11

Thermal energy is the internal energy of an object due to the kinetic energy of its molecules.

Question 12

True or False: Work is done when a force causes displacement.

Answer 12

True

Question 13

What is the unit of energy in the International System of Units (SI)?

Answer 13

Joule (J)

Question 14

Fill in the blank: Power is the rate at which _____ is done.

Answer 14

work

Question 15

What is the formula for power?

Answer 15

Power = Work / Time

Question 16

What type of energy is associated with chemical bonds?

Answer 16

Chemical energy.

Question 17

Multiple Choice: Which of the following is a renewable energy source? A) Coal B) Solar C) Natural Gas D) Nuclear

Answer 17

B) Solar

Question 18

True or False: Mechanical energy is the sum of potential and kinetic energy.

Answer 18

True

Question 19

What is elastic potential energy?

Answer 19

Elastic potential energy is the energy stored in elastic materials as the result of their stretching or compressing.

Question 20

What is work-energy theorem?

Answer 20

The work-energy theorem states that the work done on an object is equal to the change in its kinetic energy.

Question 21

Fill in the blank: The energy of motion is known as _____ energy.

Answer 21

kinetic

Question 22

What is the principle of conservation of mechanical energy?

Answer 22

In the absence of non-conservative forces, the total mechanical energy remains constant.

Question 23

What is the formula for mechanical energy?

Answer 23

ME = KE + PE

Question 24

Multiple Choice: Which of the following is an example of non-renewable energy? A) Wind B) Hydro C) Oil D) Solar

Answer 24

C) Oil

Question 25

What is a common unit for measuring power?

Answer 25

Watt (W)

Question 26

True or False: Energy efficiency is the ratio of useful energy output to total energy input.

Answer 26

True

Question 27

What is nuclear energy?

Answer 27

Nuclear energy is the energy released during nuclear fission or fusion.

Question 28

Fill in the blank: The energy stored in the nucleus of an atom is called _____ energy.

Answer 28

nuclear

Question 29

What is the difference between renewable and non-renewable energy sources?

Answer 29

Renewable energy sources can be replenished naturally, while non-renewable sources are finite and deplete over time.

Question 30

What is sound energy?

Answer 30

Sound energy is the energy carried by sound waves.

Question 31

Multiple Choice: Which form of energy is primarily associated with the motion of electrons? A) Thermal B) Electrical C) Chemical D) Mechanical

Answer 31

B) Electrical

Question 32

What is radiant energy?

Answer 32

Radiant energy is energy that travels by waves or particles, particularly electromagnetic radiation such as light.

Question 33

True or False: The efficiency of an energy conversion process is always less than 100%.

Answer 33

True

Question 34

What is the formula for calculating the work done by a force?

Answer 34

Work = Force × Distance × cos(θ)

Question 35

Fill in the blank: A machine's ability to multiply force is known as _____ advantage.

Answer 35

mechanical

Question 36

What is geothermal energy?

Answer 36

Geothermal energy is the heat from the Earth's interior used for heating or electricity generation.

Question 37

What is the role of friction in energy transformation?

Answer 37

Friction converts kinetic energy into thermal energy, often resulting in energy loss.

Question 38

Multiple Choice: Which of these is a form of mechanical energy? A) Sound B) Light C) Motion D) Heat

Answer 38

C) Motion

Question 39

What is the difference between heat and temperature?

Answer 39

Heat is the energy transferred between objects due to a temperature difference, while temperature is a measure of the average kinetic energy of particles.

Question 40

What is hydroelectric energy?

Answer 40

Hydroelectric energy is generated by harnessing the power of flowing water.

Question 41

Fill in the blank: The energy of an object at rest due to its position is called _____ energy.

Answer 41

potential