Energy and fields

Question 1

Define a force field

Answer 1

A force field is a region of space where a body experiences a force without physical contact with another body

Question 2

What makes up mechanical energy

Answer 2

Sum of kinetic and potential energy

Question 3

What direction of electric force does negative charge experience

Answer 3

Opposite direction to electric field

Question 4

Define elastic potential energy store

Answer 4

Energy store in an elastic body due to its elastic deformation

Question 5

Define a system

Answer 5

A system is an object or a group of objects

Question 6

Formula for GPE

Answer 6

GPE = mgh

Question 7

What are the energy stores

Answer 7

• Gravitational potential
• Elastic potential
• Kinetic
• Chemical
• Internal
• Nuclear
• Electric potential
• Magnetic potential

Question 8

Define gravitational potential energy store

Answer 8

Energy store for a mass due to its position in a gravitational field

Question 9

What is the work energy theorem

Answer 9

Work done = Change in mechanical energy

Question 10

Define work done

Answer 10

Work done by a force on a body is the product of the force and the displacement of the body in direction of force

Question 11

How is energy transferred from one store to another

Answer 11

• Heating
• Electrical
• Wave propagation
• Mechanical

Question 12

Define gravitational field strength

Answer 12

Gravitational field strength at a point is the gravitational force per unit mass on a mass placed at that point

Question 13

How to find EPE from Fx graph

Answer 13

Area under graph
= 0.5kx^2

Question 14

What is the work done by gravitational or electric field equal to

Answer 14

Negative of the change in gravitational or electric potential energy

Question 15

Formula for kinetic energy

Answer 15

KE = 0.5mv^2

Question 16

Define electric field strength

Answer 16

Electric field strength at a point is the electric force per unit positive charge placed at that point

Question 17

Define power

Answer 17

Power is the rate of energy transfer

Question 18

Define Principle of Conservation of Energy

Answer 18

Principle of Conservation of Energy states that in absence of external force, total mechanical energy of system is conserved

Question 19

Which direction is electric field pointing towards

Answer 19

Negative charge

Question 20

Define electric potential energy store

Answer 20

Energy store for a charged body due to its position in an electric field

Question 21

Define kinetic energy

Answer 21

Kinetic energy is the energy possessed by a body due to its motion

Question 22

What direction of electric force does positive charge experience

Answer 22

Same direction as electric field

Question 23

Formula for power

Answer 23

P
= dW/dt
= Fv

Question 24

Formula for work done

Answer 24

W = Fs cos <

Question 25

Define field strength

Answer 25

Magnitude of field