Physics 2a

Question 1

What is the difference between speed and velocity?

Answer 1

Speed is just how fast you’re going but Velocity also has the direction specified eg. 30mph north.

Question 2

How do you calculate speed?

Answer 2

distance/time.

Question 3

What does the Gradient of a distance-time graph tell you and how do you calculate it?

Answer 3

1) It tells you the speed of your object.

2) Speed= vertical/ horizontal distance/ time

Question 4

What is acceleration?

Answer 4

It is how quickly velocity is changing.

the change in velocity can be in speed or direction.

Question 5

How do you calculate acceleration and what is it’s unit?

Answer 5

1) Change in velocity/ time taken. (change in velocity= final velocity- initial velocity).
2) m/s squared

Question 6

What is a resultant force?

Answer 6

The overall force on a point or object.

Question 7

What unit are forces measured in?

Answer 7

Newtons

Question 8

How do you calculate a resultant force/

Answer 8

You do a force from one direction- the force from the other if it equals zero then the object has no resultant force.

Question 9

What does it mean for an object if it does have a resultant force?

Answer 9

It will accelerate or decelerate.

Question 10

What happens if there is no resultant force on a moving object?

Answer 10

It will continue at the same velocity, not become stationary.

Question 11

What are the five different forms that acceleration can result in?

Answer 11

1) starting
2) Stopping
3) Speeding up
4) Slowing down
5) Changing direction

Question 12

how do you calculate force?

Answer 12

mass (kg) x Acceleration (metres per second squared)

Question 13

what forces will two objects exert on each other when they interact?

Answer 13

equal and opposite forces.

Question 14

Where do you get friction and what does it do?

Answer 14

1) You get friction between two surfaces in contact, or when a object passes through a fluid.
2) It acts in the opposite direction to movement and slows the object down.

Question 15

What is terminal velocity?

Answer 15

When an object stops accelerating and reaches it’s maximum speed and continues at a steady speed.

Question 16

What does air resistance do?

Answer 16

It causes things to fall at different speeds depending on the surface area.

Question 17

What would opening a parachute do to a skydiver’s terminal velocity?

Answer 17

It would bring the number down by a lot.

Question 18

How do you calculate stopping distance?

Answer 18

The sum of the thinking distance and the braking distance.

Question 19

What is reaction time and what is the distance covered during this time called?

Answer 19

1) The time between the driver spotting a hazard and taking action.
2) Thinking distance.

Question 20

What are the two main factors that affect your thinking distance?

Answer 20

1) How fast you’re going.

2) How dopey you are (could be affected by tiredness, drugs or alcohol).

Question 21

What is braking distance?

Answer 21

The distance the car travels under braking force.

Question 22

What are the four main factors that affect braking distance?

Answer 22

1) How fast you’re going.
2) How good your brakes are.
3) How good your tyres are.
4) How good the grip is.

Question 23

How do you calculate work done?

Answer 23

Force(N) x distance(m) = work done(J)

Question 24

What is work done?

Answer 24

When a force moves an object through a distance.

Question 25

How do you calculate gravitational potential energy?

Answer 25

mass x g(10N/kg) x height.

Question 26

How do you calculate kinetic energy?

Answer 26

1/2 x mass x speed squared.

Question 27

What do these symbols mean when working out the kinetic energy transferred by a car?
1/2 x m x v squared = F x d

Answer 27

m= mass of car and passengers(in kg)
v= speed of car(in m/s)
F= maximum braking force (in N).
d= braking distance (in m)

Question 28

What do falling objects convert potential energy to?

Answer 28

Kinetic energy.

Question 29

What two other types of energy is kinetic energy often transferred to?

Answer 29

heat and sound.

Question 30

what happens to elastic potential energy when force is removed from it?

Answer 30

It is converted into kinetic energy.

Question 31

What is a positive static charge caused by?

Answer 31

Electrons moving else where.

Question 32

What is the build up of static caused by?

Answer 32

Friction

Question 33

What happens when two insulating materials are rubbed together?

Answer 33

negatively charged