Force

Question 1

What are the 2 types of force?

Answer 1

Internal

External

Question 2

What is internal force?

Answer 2

Force generated by the sports performer with the contraction of skeletal muscles

Question 3

What is an external force?

Answer 3

Forces that come from outside the body and act upon in

Question 4

What are the 2 types of external force?

Answer 4

Vertical and horizontal

Question 5

What are the 2 horizontal forces?

Answer 5

Friction

Air resistance

Question 6

What are the 2 vertical forces?

Answer 6

Weight

Reaction

Question 7

What is the definition of friction?

Answer 7

The force that opposes the motion of 2 solid surfaces in contact

Question 8

What is the definition of weight?

Answer 8

The gravitational force that the earth exerts on a body

Question 9

What is the definition of air resistance?

Answer 9

The force opposing the motion of a body travelling through the air

Question 10

What is the definition of reaction?

Answer 10

The equal and opposite force exerted by a body in response to the action force placed upon it.

Question 11

What is the definition of net force?

Answer 11

The sum of all forces acting on a body when all the individual forces have been considered

Question 12

What happens if the net force is 0?

Answer 12

There is no change in motion, two or more forces are balanced so the body will remain at rest or uniform velocity.

Question 13

What happens if there is a positive net force?

Answer 13

There is a change in motion, two or more forces are unbalanced so the body will accelerate, change direction or change shape.

Question 14

What happens if there is a negative net force?

Answer 14

There is a change in motion, two or more forces are unbalanced so the body will decelerate, change direction or change shape.

Question 15

Where does weight force act?

Answer 15

From the centre of mass downwards

Question 16

How do you increase weight force?

Answer 16

The greater the mass, greater the weight force pulling the body downwards

Question 17

When is weight force present?

Answer 17

Always

Question 18

When is reaction force present?

Answer 18

When 2 bodies are in contact

Question 19

When will a body accelerate upwards?

Answer 19

When the reaction force is larger than the weight force

Question 20

What affects friction?

Answer 20

Roughness of ground surface
Roughness of contact surface
Temperature of surfaces in contact
Reaction force

Question 21

How do you maximise friction?

Answer 21

Rough ground surface eg track
Rough contact surface eg spikes
High temperature eg F1 tires warm up lap
Bigger reaction eg more mass, more reaction, more friction

Question 22

How do you minimise friction?

Answer 22

Smooth contact surface
Smooth ground surface
Smaller surface area between the 2 surfaces in contact

Question 23

What is air resistance affected by?

Answer 23

Velocity
Shape
Frontal cross sectional area
Smoothness of surface
Density of air
Mass of body

Question 24

Explain how velocity affects air resistance

Answer 24

As velocity increases so does air resistance

Question 25

Explain how shape affects air resistance

Answer 25

The more aerodynamic the less air resistance

A teardrop shape is the most streamlined

Question 26

Explain how frontal cross sectional area affects air resistance

Answer 26

The smaller the frontal cross sectional area the less air resistance

Question 27

Explain how smoothness of surface affects air resistance

Answer 27

The smoother the surface the less air resistance

Question 28

Explain how density of air affects air resistance

Answer 28

The less dense the air the less air resistance

Question 29

Explain how mass of body affects air resistance

Answer 29

The larger the mass the less air resistance will affect it as it has a higher inertia

Question 30

What are some sports that minimise friction

Answer 30

Cycling, skating and curling