Topic 2 And 3

Question 1

What is a scalar quantity

Answer 1

Magnitude but no specific diretcion

Question 2

What is a vector quantity

Answer 2

Has both magnitude and specific direction

Question 3

What is displacement

Answer 3

Vector quantity

Distance an object moves in a straight line from starting point to finish

Question 4

What is distance

Answer 4

Distance is how far an object moves.
Distance is a scalar quantity.
This is because it contains a magnitude (size) but not a direction.

Question 5

What is speed

Answer 5

Scalar quantity

Speed does not have direction it only has a magnitude

Question 6

What is velocity

Answer 6

Vector quantity as it has both magnitude and direction

Question 7

What kind of quantity is mass and energy

Answer 7

Scalar quantity

Question 8

On a distance time graph what happens if the speed increases

Answer 8

The object will travel a longer distance in the same amount of time
The gradient will become steeped

Question 9

How do you work out the speed on a distance time graph

Answer 9

Work out the gradient

Question 10

What happens when the speed on a distance time graph decreases

Answer 10

If an object’s speed decreases, then the object will travel a shorter distance in the same amount of time.
The slope (gradient) of the distance-time graph will become less steep.

Question 11

What axis are distance and time on

Answer 11

Distance on y axis and time on x axis

Question 12

What does the area under a velocity time graph represent

Answer 12

Distance travelled by an object

Question 13

What do light gates do

Answer 13

Record how long it takes for an object to pass through them - can be used to calculate speed

Question 14

How can you set up a light gate experiment

Answer 14

Length of a piece of card is measured with a ruler and attached to a trolley
The trolley is rolled down the ramp so that the card passes through the light gate

Question 15

What must happen for there to be motion in a circle

Answer 15

There must be a resultant force that is known as the centripetal force that acts towards the centre of the circle

Question 16

What does Newton’s 3rd law state

Answer 16

Whenever two objects interact, the forces that they exert on each other are equal and opposite which shows an equilibrium

Question 17

What does Newton’s third law suggest about collision interactions

Answer 17

In collisions this means that the force of one object on the other is equal in magnitude but opposite in direction

Question 18

What is momentum

Answer 18

The mass of an object multiplied by its velocity

Question 19

What is the law of conservation of momentum

Answer 19

Momentum cannot be created or destroyed

Question 20

Newton’s 2nd law equation

Answer 20

Force = change in momentum/ time

Question 21

Describe the energy stores and transfers as an object moves upwards

Answer 21

object’s energy is initially in the kinetic store as it moves upwards.
The object’s energy is slowly transferred from the kinetic store to the gravitational potential store as it slows down and climbs higher.
Once the object reaches its highest point, all of it’s energy is in the gravitational potential store.

Question 22

Explain the energy transfers on an object that is accelerated by a constant force

Answer 22

Work is done by a force on an object.

This work is converted to the object’s kinetic store.

Question 23

Describe the energy transfers of an object hitting an obstacle

Answer 23

object’s energy is in the kinetic store to begin with because it is moving.
When the object collides with the obstacle, energy is converted to:
The kinetic store of the obstacle (making it move),
The thermal store of the object and the obstacle

Question 24

Explain the energy transfers from bringing water to a boil in an electric kettle

Answer 24

Energy transfers from the electrical store of the mains power supply to the thermal store of the water.

Question 25

Explain the energy transfers for a vehicle slowing down

Answer 25

the vehicle’s energy is in the kinetic store.

The brakes do work slowing the car down. During this process, energy is dissipated (lost) through heat and sound.

Question 26

How does lubrication reduce unwanted energy transfer

Answer 26

Reduces frictional forces between surfaces of objects that are rubbing together
Lubricants are normally liquids

Question 27

How does thermal insulation reduce unwanted energy transfer

Answer 27

Use loft insulation, double glazing, fit carpets eg to stop heat being lousy through the roofs windows walls and floor

Question 28

How does thickness of walls affect thermal conductivity

Answer 28

We can decrease the rate a house cools down by:
Having thicker walls
Having walls made from material with a lower thermal conductivity.

Question 29

How can efficiency be increased

Answer 29

By reducing wasted energy transfers so more of the input energy is usefully transferred. Lubrication can reduce the friction between objects and therefore increase the amount of useful energy transferred

Question 30

What happens when there are energy transfers in a closed system

Answer 30

There is no net change to the total energy in that system