Unit 1 APPLICATION OF FORCES AND TRANSFER OF ENERGY

Question 1

SI unit for Force:

Answer 1

Newton (N)

Question 2

Apparatus to measure Force

Answer 2

• Spring Balance
• Dynamometer

Question 3

In what ways are Friction advantageous?

Answer 3

• Improved grip
• Prevents slipping
• Writing
• Slowing down or stopping objects
• Moving on muddy or wet surfaces
• Door stoppers

Question 4

Types of Forces:

Answer 4

• Magnetic Force
• Elastic Force
• Frictional Force

Question 5

Definition of Elastic Force:

Answer 5

• Elastic Force is a contact force that comes into play when an object is stretched or compressed from its original shape.

Question 6

Definition of Gravitational Force:

Answer 6

• As long as objects possess mass, they can exert an attractive force on each other.

Question 7

Can exert force when Pushed or Pulled (from its original form)

Answer 7

Elastic Force

Question 8

Definition of Gravitational Field Strength:

Answer 8

It tells us the amount of gravitational force it exerts on every 1 kg of mass.

Question 9

SI unit of time

Answer 9

second (s)

Question 10

Relationship between mass of an object and its gravitational field strength

Answer 10

The greater the mass of the object, the stronger its gravitational field strength

Question 10

SI unit of mass

Answer 10

kilogram (kg)

Question 11

SI unit of electric current

Answer 11

ampere (A)

Question 11

SI unit of time

Answer 11

meter (m)

Question 12

How is gravitational field strength expressed?

Answer 12

N/kg (denoted as “g”)

Question 12

SI unit of temperature

Answer 12

kelvin (K)

Question 13

Characteristics of a Significant Gravitational Force:

Answer 13

• The force is strong enough to move or affect the objects involved.
• One or both objects typically have a substantial mass

Question 14

Define the effect of forces:

Answer 14

When two or more objects interact, they can exert forces on each other, leading to a possible transfer of energy between them and observable changes in these objects.

Question 14

Weight is referred to as..

Answer 14

The total amount of gravitational force acting on an object of any mass.

Question 15

Definition of mass

Answer 15

The amount of matter in an object

Question 16

Definition

Question 17

W = m x g

Answer 17

kg x N/kg (g) = N

Question 18

Definition of magnetic force

Answer 18

It is a force exerted between magnets or between a magnet and magnetic substances.

Question 19

Characteristics of Mass:

Answer 19

• The mass remains unchanged in different locations
• SI unit: Kilogram (kg)
• Measuring instrument: Beam balance, electronic balance

Question 20

Characteristics of Weight:

Answer 20

• The weight of the object varies in different locations
• SI unit: Newton (N)
• Measuring instrument: Spring Balance, Dynamometer

Question 21

Definition of Moment of a Force

Answer 21

It is a measure of the turning effect of a force applied to a point on an object

Question 21

What is pressure defined by

Answer 21

Force per Unit Area

Question 22

M = F × d

Answer 22

Moment (Nm) = Force (N) × Distance from Pivot (m)

Question 23

W = m × g

Answer 23

Weight N() = mass (kg) x gravitational field strength (N/kg)

Question 24

W = F x s

Answer 24

Work done (J) = Force (N) x Distance (m)

Question 25

Why do we feel Cold and face Low Surrounding Pressure when at a high up place compared to a place lower on the ground.

Answer 25

The higher you go, the less air there is in the atmosphere hence there is less air mass pressing you down. (Gravity pulling air particles down typically). The cold is due to thinner air's reduced ability to retain heat, and the low pressure affects your body as it adapts to the changes in oxygen levels and the overall environment.

Question 26

Conditions for Work NOT to be considered done (2 Ways)

Answer 26

- The object does not move even when a Force is applied - The direction of motion of the object is not the same as the applied force.

Question 27

Why is it harder to push the same mass object up-hill compared to on flat ground?

Answer 27

- Up-hill: You are working against BOTH Friction and Gravity acting on the object - On flat ground: The force you apply only needs to overcome the friction acting on the object.

Question 28

How does an increase in energy occur?

Answer 28

- Transferring energy - Converting energy

Question 28

What is the law of conservation of energy?

Answer 28

Energy cannot be created nor destroyed

Question 29

What are Sources of Energy?

Answer 29

Energy sources refer to various natural phenomena (sunlight) or natural processes (fossil fuels) from which energy stored in them can be harnessed and converted to usable forms.

Question 30

Examples of non-renewable energy sources (2 types)

Answer 30

- Fossil Fuels (takes very long to form -> millions of years) - Nuclear (composed with finite resources -> Uranium)