Forces

Question 1

What is a force?

Answer 1

A push or a pull

Question 2

What unit is used to measure forces?

Answer 2

Newtons (N)

Question 3

What is a net force

Answer 3

An unbalanced force

Question 4

Forces can be…

Answer 4

..External forces or Internal forces

Question 5

List some external forces:

Answer 5

• Gravity
• Friction
• Drag force (type of friction)
• Contact by external object

Question 6

List an internal force:

Answer 6

Contraction of skeletal muscles

Question 7

What does friction do and when does it occur?

Answer 7

• Friction opposes motion
• Occurs when 2 surfaces come in contact with one another

Question 8

List some examples of sports trying to increase friction

Answer 8

• Players wearing studs
• Grip on gloves
• Tread on tyres
• Chalk on gymnast’s hands

Question 9

List some examples of sports trying to decrease friction

Answer 9

• Ice skating
• Down hill skiing
• Ten pin bowling
• Slip and slide

Question 10

What does gravity do?

Answer 10

Causes objects to fall downwards, towards ground.

Question 11

What is the speed of objects falling down due to gravity?

Answer 11

9.8m/s^2

All objects fall at speed, only difference might be air resistance etc.

Question 12

What is mass?

Answer 12

The amount of matter possesed by an object

Doesn’t change

Question 13

What is weight?

Answer 13

Weight = mass x gravity.

Weight changes in places where gravity changes (space/planets/etc.)

Question 14

Describe how gravity and air resistance affect objects of a projectile

Answer 14

Gravity affects the vertical component of a projectile whilst air resistance affects the horizontal component of a projectile.

Question 15

Drag force is experienced by which two main factors?

Answer 15

Air resistance and Water resistance

Air is considered a fluid because it flows

Question 16

Describe the number of particles you hit in various situations on terms of air/water resistance.

Answer 16

• The more particles you hit, the more resistance felt.
• If air/water pressure is high, more particles are hit.
• If going fast, more particles are hit.
• If big, more particles are hit.

Question 17

List some factors that affect drag force:

Answer 17

• Air density
• Cross sectional area of body (surface area)
• Shape
• Nature of surface area
• Speed

More speed = more drag