Energy

Question 1

What is the unit of energy?

Answer 1

Joule (J)

Question 2

True or False: Energy can be created or destroyed.

Answer 2

False

Question 3

Fill in the blank: The law of conservation of energy states that energy cannot be ________ or ________.

Answer 3

created; destroyed

Question 4

What is kinetic energy dependent on?

Answer 4

Mass and velocity of the object

Question 5

Equation for kinetic energy

Answer 5

Kinetic energy = 1/2 x mass x speed^2

Question 6

What is the formula for gravitational potential energy?

Answer 6

PE = mgh

Question 7

In the formula PE = mgh, what does each variable represent?

Answer 7

PE = potential energy, m = mass, g = acceleration due to gravity, h = height

Question 8

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

Answer 8

B) Solar

Question 9

What is the definition of energy efficiency?

Answer 9

The ratio of useful energy output to total energy input

Question 10

True or False: A perfectly efficient machine would convert all input energy to useful work.

Answer 10

True

Question 11

What is the principle behind a hydroelectric power station?

Answer 11

Converting kinetic energy of flowing water into electrical energy

Question 12

Fill in the blank: The energy stored in food is an example of ________ energy.

Answer 12

chemical

Question 13

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

Answer 13

Renewable sources can be replenished naturally, while non-renewable sources cannot.

Question 14

Calculate the gravitational potential energy of a 5 kg object at a height of 10 m.

Answer 14

490 Joules

Question 15

What is thermal energy?

Answer 15

The internal energy present in a system due to the kinetic energy of its particles

Question 16

Multiple Choice: Which energy transformation occurs in a toaster? A) Electrical to Thermal B) Thermal to Kinetic C) Kinetic to Chemical

Answer 16

A) Electrical to Thermal

Question 17

What is work done equal to?

Answer 17

Force multiplied by distance

Question 18

True or False: Power is the rate of doing work.

Answer 18

True

Question 19

What is the formula for calculating power?

Answer 19

Power = Work done / Time taken

Question 20

Fill in the blank: The total energy in a closed system remains ________.

Answer 20

constant

Question 21

What type of energy is associated with the motion of particles in a substance?

Answer 21

Thermal energy

Question 22

Multiple Choice: Which energy source is derived from the sun? A) Wind B) Fossil Fuels C) Solar

Answer 22

C) Solar

Question 23

What is the main disadvantage of non-renewable energy sources?

Answer 23

They can deplete over time and contribute to pollution.

Question 24

What is the energy transformation that occurs in a battery?

Answer 24

Chemical energy to electrical energy

Question 25

True or False: All forms of energy can be converted into each other.

Answer 25

True

Question 26

What does the efficiency of a machine depend on?

Answer 26

The ratio of useful energy output to total energy input