Forces, movement, shape and momentum

Question 1

Effects of forces between bodies

Answer 1

Forces can act on a body to change the velocity (speed, direction or both)
- forces can change the shape of a body, stretching it squishing it or twisting it.

Question 2

What are the 9 different types of forces

Answer 2

Gravitational, weight, friction, electrostatic, air resistance (drag), tension, up thrust, lift, thrust

Question 3

Difference between scalar and vector quantities

Answer 3

scalars are quantities with only magnitude (size)

vectors are quantities with magnitude (size) and direction

Question 4

How does friction work

Answer 4

Friction is caused by surfaces rubbing. The force always acts in the opposite direction to motion.

Question 5

Force equation

Answer 5

Force = Mass x Acceleration.

Question 6

Weight equation

Answer 6

Weight = mass x gravitational field strength (10N/kg)

Question 7

Stopping distance equation

Answer 7

Stopping distance = Thinking distance + Breaking distance

Question 8

Factors affecting thinking distance

Answer 8

Tiredness
Alcohol
speed of the car
Drugs

Question 9

Factors affecting braking distance

Answer 9

Road conditions
Tyre conditions
Brake conditions
speed of the car
mass of the car

Question 10

Why do falling objects reach a terminal velocity

Answer 10

• only force is weight, drag is proportional to velocity
• object accelerates downwards
• s it accelerates the velocity, drag increases also, meaning a smaller resultant force downwards, smaller acceleration
• Until object reaches a speed where drag = weight = no acceleration

Question 11

What is elastic behaviour

Answer 11

Ability of a material to recover to original shape after force is removed