LEARN!

Question 0

How do brakes slow an object down

Answer 0

Apply friction

Transfers kinetic energy from the car into other forms

Question 1

How does rain effect stopping distances

Answer 1

Reduces friction

Question 2

How do you know ifs wave is longitudinal

Answer 2

It will have compressions and rarefractions

Question 3

Transverse waves

Answer 3

The oscillations are PERPENDICULAR to the direction of energy transfer

Question 4

Longitudinal waves

Answer 4

The oscillations are PARALLEL to the direction of energy transfer

Question 5

Example of a transverse wave

Answer 5

EM waves

A ripple

Question 6

Example of a longitudinal wave

Answer 6

Sound
Ultrasound
Shock waves

Question 7

What is the amplitude of a wave

Answer 7

Distance from rest to crest

Question 8

What is the normal

Answer 8

Imaginary line that is perpendicular to the surface

Question 9

What is diffraction

Answer 9

When waves spread out after passing through a small gap

Question 10

Why do rays get refracted

Answer 10

Ray hits a material with a different density

So speed will change

Question 11

Describe how electromagnetic radiation is used in security marking

Answer 11

U-V radiation is absorbed by certain chemicals with fluorescent properties

Question 12

What is a resultant force?

Answer 12

A single force which has the same effect as all the forces acting together

Question 13

Why is a 13A fuse too big for 3.7A

Answer 13

Will allow too great a current through and not provide protection

Question 14

Why is a switch not closed all the time

Answer 14

Current flowing through a resistor will warm it up so the resistance of the resistor will change

Question 15

How do airbags reduce force acting on a driver

Answer 15

• increases time taken for the force to act
• momentum changes slowly
• decreases forces acting on driver

Question 16

How does the speed of a truck effect the size of resistant forces it experiences

Answer 16

As speed increases, resultant force increases

Question 17

Why do falling objects reach terminal velocity

Answer 17

• resistive forces act
• these increase as the object accelerates
• eventually these will balance and the object will reach terminal velocity

Question 18

How do parachutes decrease a skydivers terminal velocity

Answer 18

• increases air resistance

- forces acting are balanced at a lower speed therefore terminal velocity is lower

Question 19

What is a reaction time

Answer 19

Time it takes you to react from an event

Question 20

Describe the differences between a scalar and a vector quantity

Answer 20

Scalar quantities have magnitude

Vector quantities have both direction and magnitude

Question 21

On a distance time graph what is a steady speed shown by

Answer 21

Straight line

Question 22

If an object travels at a steady speed is there a resultant force

Answer 22

No

Question 23

Two factors that effect a reaction time

Answer 23

Drugs
Alcohol
Weather

Question 24

What will happen if you increase the cars maximum breaking force

Answer 24

It will decrease the braking distance

Question 25

Why is fruit sterilised with a gamma ray

Answer 25

Treating fruit with radiation kills bacteria

This means the fruit will stay fresh for longer

Question 26

Why can x-rays be used to treat cancer

Answer 26

They are ionising

So kill cancer cells

Question 27

Why does something echo in a hall but not in a field

Answer 27

The sound is refracted off the walls of the hall and there are no walls outside