Forces

Question 1

what is the definition of a force?

Answer 1

a push or pull of one body on another.

Question 2

name 2 different forces

Answer 2

gravitational

electrostatic

Question 3

what is friction?

Answer 3

a force that opposes motion

Question 4

what forces act on a falling object? and why does it reach terminal velocity?

Answer 4

weight is pulling the object down and air resistance if pushing it back up. the weight force is stronger than the air resistance when the object first starts to fall so it accelerates. the air resistance increases as the object falls faster till the air resistance matches the opposing force and it reaches terminal velocity where the object stopped accelerating

Question 5

what factors effect thinking distance?

Answer 5

• drinking
• tiredness
• age

Question 6

what factors effect breaking distance?

Answer 6

• speed
• road conditions
• weather
• mass of vehicle
• tyres
• breaking force

Question 7

what is breaking distance and what effect does speed have on it?

Answer 7

breaking distance is the distance it takes from the moment the brakes are activated till the veichle is stationary. if speed doubles, the breaking distance increases by ×4

Question 8

what is thinking distance and what effect does speed have on it?

Answer 8

the distance you travel before you react. If the speed increases the reaction time does not increase but the distance increases as you will travel further in the space of time.

Question 9

what is the relationship between the extension to the load on a spring? and what would it’s graph look like?

Answer 9

the extension is directly proportional to the load- Hooke’s law.
the graph would be a straigh line through the origin.

Question 10

what is the relationship between the extension to the load on a rubber band? and what would it’s graph look like?

Answer 10

As the weight increases, the extension increases. but they are not directly proportional. This can be seen because the line of best fit would
be a curve rather than a straight line going through zero. So Hooke’s Law does not
apply.

Question 11

on a velocity and time graph how do you work out the distance travelled?

Answer 11

the area under the line

Question 12

what is a scalar?

Answer 12

a scalar quantity has a size or magnitude but no direction.

e.g. mass or temperature

Question 13

what is a vector?

Answer 13

vector quantities have a size or magnitude and a direction.

e.g. force or velocity

Question 14

what is a moment?

Answer 14

the force to turn things like a spanner