Energy transfer

Question 1

The faster you’re going the ……… the breaking force needed to stop you

Answer 1

bigger

Question 2

What is stopping distance made up of?

Answer 2

Thinking and breaking distance, from when the driver sees the hazard to when the car stops moving completely

Question 3

What is the breaking distance affected by?

Answer 3

How fast you’re going

How dopey you are - drugs, tiredness, alcohol or a careless attitude affects this

Question 4

What external factors reduce the stopping distance?

Answer 4

Bad visibility like rain or bright lights so the time the driver has to break is shortened as they don’t see the hazard

Question 5

What four factors affect breaking distance?

Answer 5

How fast you’re going - faster the further it takes to stop
Quality of breaks - worn will take longer to effectively slow you down
Tyre quality - a minimum tread depth of 1.6mm is needed to get rid of water, debris can cause skidding
How good the grip is - depending on road surface, weather conditions, tyres

Question 6

What is the definition for work done?

Answer 6

When a force moves an object through a distance, energy is transferred and work is done.

Question 7

Whenever something moves something else is providing some sort of …. to …. it.
The thing putting in the effort needs a supply of ….
It then does ….. by moving the object, so it ….. the energy it ….. as fuel, into other …… .
Wasted or ……, the energy transferred is still ………. ……

Answer 7

effort to move it
energy
work, transfers, receives, forms
used, work done

Question 8

What is the formula for work done?

Answer 8

Work done (J) = force (N) X distance (m)
W of FxD in a triangle form

Question 9

What is gravitational potential energy?

What is the equation?

Answer 9

The energy an object has because of its vertical position in a gravitational field
GPEnergy (J) = mass x g x height

Question 10

What happens when an object is raised vertically? (2 ish)

Answer 10

Work is done against the force of gravity, and the object gains GPEnergy

Question 11

What is the gravitational field strength on the planet?

Answer 11

10Nkg

Question 12

What is kinetic energy?

What is the equation?

Answer 12

The energy an object has when it is moving

KE = 1/2 X mass X speed-squared

Question 13

Kinetic energy depends on the …. and … of the object.

The more it … the ….. it will go, so the …. it’s … energy will be.

Answer 13

mass , speed

weighs, faster, bigger it’s kinetic

Question 14

Kinetic energy transferred is ….
When a car is moving it has ….
What has to happen to this energy when a car needs slowing down?
So the …. energy is ……. into ….. energy and …. between the wheels and the break pads, causing the ….. of the … to increase.

Answer 14

work done
kinetic energy
it needs to be converted into other types, due to conservation
kinetic, converted, heat, friction, temperature, breaks

Question 15

Kinetic Energy Transferred =

1/2 X M X Vsquared =

Answer 15

Work done by brakes
F x d
m is mass of car in kg
v is speed of car in m/s
f is maximum breaking force in N
d is breaking distance in meters

Question 16

What happens to an object’s potential energy when it falls?

Answer 16

It’s converted into kinetic energy, heat or sound

The further it falls the faster it goes

Question 17

What is the equation for the potential energy lost that’s transferred into kinetic energy?

Answer 17

K energy gained= Potential energy lost

Question 18

What do some meteors and space shuttle shave when they enter the earth’s atmosphere?
What happens to some of their kinetic energy when they enter, why and what is done?
What happens due to to friction?

Answer 18

They have a very high kinetic energy
Friction due to collisions with particles transfers the energy into heat and work is done.
The temps can be so extreme that meteors burn up before they hit the earth

Question 19

What are meteorites?

Answer 19

The meteors that can make it to the earth’s surface

Question 20

How are space shuttles made so that they don’t burn up in the atmosphere?

Answer 20

They have heat shields made from special materials which lose heat quickly allowing the shuttle to reenter.

Question 21

Elastic objects store energy as …..

Answer 21

elastic potential energy

Question 22

When you apply a force to an object you cause it to ……. and …… … …….
Any object that can go back to its original shape after the force has been removed is an …….. …….

Answer 22

stretch and change in shape

elastic object

Question 23

What is done to an elastic object to change its shape?

The energy is not …. by the object but …. as ….. ….. ….. .

Answer 23

Work

lost, stored as elastic potential energy

Question 24

Elastic potential energy is then converted into …. ….. when a force is removed from an elastic object.
So the object ….

Answer 24

kinetic energy

returns to its original shape

Question 25

The extension, e, of a …. spring is …. …… to force applied, F.
The extension is measure in ….. , and the the force is measure in …

Answer 25

stretched spring, directly proportional
meters
newtons

Question 26

What is the equation for spring extension?

What do the letters mean?

Answer 26

F= K x e

F is force, K is the spring constant, e is the extension, m

Question 27

What does the spring constant value depend on?

What is it measured in?

Answer 27

The material being stretched

Newtons per meter, N/m

Question 28

But what stops the direct proportion between the spring and force?

Answer 28

When the force gets too big, past the limit of proportionality, the material will be permanently stretched. When the force is removed the material will be longer.

Question 29

Describe the graph showing force (y axis) against extension (x axis), so the shape of the curve….
What is P?

Answer 29

It rises in a straight line then at point P the line curves so the force isn’t proportional to the extension
P is where the object is under the maximum force where it can still extend proportionally, the limit of proportionality.