4.6.1 - Forces and Energy

Question 1

What is a scalar quantity?

Answer 1

A quantity that has magnitude (size) only

Question 2

Give an example of scalar quantity.

Answer 2

• Distance
• Speed

Question 3

What is a vector quantity?

Answer 3

A quantity that has magnitude (size) and direction

Question 4

Give an example of a vector quantity.

Answer 4

• Forces

Question 5

What is a force?

Answer 5

A push, pull or twist. Can be a contact or a non-contact force

Question 6

How are forces shown?

Answer 6

Arrows

Question 7

What is a contact force?

Answer 7

Force exerted between two objects while touching

Question 8

Name a example of a contact force.

Answer 8

• Friction
• Air Resistance
• Tension

Question 9

What is a non-contact force?

Answer 9

A force that affects an object without coming into contact with it

Question 10

Name an example of a non-contact force.

Answer 10

• Gravitational Forces
• Electrostatic Forces
• Magnetic Forces

Question 11

How can you measure a force?

Answer 11

With a Newton metre

Question 12

What are the units for force?

Answer 12

Newtons (N)

Question 13

What is a resultant force?

Answer 13

The overall acting on an object

Question 14

How is resultant force calculation?

Answer 14

Subtraction of the opposite forces

Question 15

What is a free body diagram?

Answer 15

A simplified drawing showing the forces acting on an object

Question 16

What are balanced forces?

Answer 16

Equal sized forces in opposite directions

Question 17

What effects do balanced forces have on a stationary object?

Answer 17

Doesn’t move it.

Question 18

What effects do balanced forces have on a moving object?

Answer 18

It stays at a constant speed

Question 19

What are unbalanced forces?

Answer 19

Forces of unequal size acting in opposite directions

Question 20

What effect do unbalanced forces have?

Answer 20

Moves it in the direction of the largest force

Question 21

What is work done?

Answer 21

Energy transferred by a force

Question 22

How is work done calculation?

Answer 22

Work Done = Force x Distance

Question 23

What is the relationship between 1 joule and 1 newton-metre?

Answer 23

They are the same

Question 24

Define mass

Answer 24

Amount of particles that make up an object

Question 25

Define weight

Answer 25

Force acting on an object due to the pull of gravity

Question 26

What is the formula for calculating weight?

Answer 26

Weight = Mass x Gravitational Field Strength

Question 27

What are the units for weight?

Answer 27

Newtons (N)

Question 28

What are the units for mass?

Answer 28

Kilograms (kg)

Question 29

What are the units for Gravitational Field Strength?

Answer 29

Newtons per Kilograms (N/kg)

Question 30

Describe the relationship between weight and mass of an object.

Answer 30

Directly Proportional

Question 31

What is the value of Gravitational Field Strength on Earth?

Answer 31

9.8 N/kg

Question 32

What is Gravitational Potential Energy?

Answer 32

The energy stored by an object lifted up against the force of gravity

Question 33

How is Gravitational Potential Energy calculated?

Answer 33

Gravitational Potential Energy = Mass x Gravitational Field Strength x Height

Question 34

What happens to an elastic object if stretched?

Answer 34

It returns to the original shape

Question 35

What happened to an inelastic object if stretched?

Answer 35

Doesn't return to the original shape

Question 36

What are the units for spring constant?

Answer 36

Newtons per metre (N/m)

Question 37

Give an example of a material that shows elastic deformation.

Answer 37

Springs

Question 38

Give an example of a material that shows inelastic deformation.

Answer 38

Bluetack

Question 39

Describe the relationship between force and extension.

Answer 39

Directly Proportional

Question 40

How is extension calculated?

Answer 40

Extension = Force / Spring Constant

Question 41

What is the units for extension?

Answer 41

Metres (m)

Question 42

What is the units for force?

Answer 42

Newtons (N)

Question 43

What is the units for Spring Constant?

Answer 43

Newtons per Metre (N/m)

Question 44

What is the limit of proportionality?

Answer 44

The point beyond which Hooke's law is no longer true when stretching a material

Question 45

What is Elastic Potential Energy?

Answer 45

Energy stored in squashed, stretched or twisted materials.

Question 46

How is Elastic Potential Energy calculated?

Answer 46

Elastic Potential Energy = 0.5 x Spring Constant x Extension^2

Question 47

What are the units for Elastic Potential Energy?

Answer 47

Joules (J)

Question 48

What are the units for Spring Constant?

Answer 48

Newton per Metre (N/m)

Question 49

What are the units for Extension?

Answer 49

Metres (m)