harder

Question 1

How do gases exert pressure?

Answer 1

The particles move in high speed , random directions.
Collision with the walls of the container exerts a force- a net force on the inside of the container (surface) determines the pressure

Question 2

How does temperature affect pressure?

Answer 2

The more temperature, the faster the particles move, the more frequently the particles collide with the container walls, the more force is exerted resulting in more pressure.

Question 3

what is the atmospheric pressure on earth?

Answer 3

100 kilo pascals

100,000 pascals

Question 4

Describe up thrust

Answer 4

A force that occurs whenever a body is immersed within a fluid.
Because of a pressure difference between the top and bottom fluid

Question 5

What happens when the atmospheric pressure is greater inside a ballon that it’s surroundings?

Answer 5

Question 6

What is inertia ?

Answer 6

How difficult it is to change the velocity of a body.

The greater mass, the greater interia

Question 7

Define momentum

Answer 7

How difficult it is to stop a moving body. The two factors affecting this are mass and velocities.
(A vector value)

Question 8

What is the deforming force?

Answer 8

Stretching , compressing or bending a body to change the shape

Question 9

What does it mean for a material to be brittle?

Answer 9

It has all linear sections, will snap instead of stretching after the elastic limit.

Question 10

What is a moment?

Answer 10

The moment of a force is the measure of its turning effect, about a pivot.

the greater the moment , the easier it is to rotate a body

Question 11

What is formula for moment’s?

Answer 11

M= d ✖️force

d is the perpendicular distance from the pivot to the the line of action of force (m)

Question 12

How can the moment of the force be increased?

Answer 12

🟢Increasing the size of the force

🟢increasing the perpendicular distance from thepivot

Question 13

What it the mechanical advantage of gears?

Answer 13

Output cog radius➗input cog radius

Largest value always as the numerator

Question 14

What happens to a car when travelling up hill? (Gears)

Answer 14

🟢you change to a lower gear
🟢the means input gear is a small gear is connected to a larger gear
🟢a input  larger moment 
🟢an output smaller moment
🟢causing the wheel to turn more slowly 

*Large mechanical advantage

Question 15

What is the symbol for a diode?

Answer 15

A circle with a triangle , line at the end pointing in the direction of current

Question 16

What is the symbol for an LEd

Answer 16

The symbol of a diode with two arrows coming out of the circle

Question 17

How much charge does an electron carry?

Answer 17

1.6 ✖️10^-19 coulombs

Question 18

Describe the IV graph for a filament light bulb

Answer 18

🔺The resistance increases with p.d
🔺As the resistance increases as it is getting hotter
🔺Non - linear circuit element

Question 19

What is a sensor circuit?

Answer 19

A circuit that turns a component on or off automatically in response to external stimuli

Question 20

Why are their differences in voltage between the wires?

Answer 20

The cell/ battery creates chemical reactions which bunch up the electrons in places of the wire. So the electrons will travel from a high point to a low point , creating a p.d

Question 21

What is magnetic flux density?

Answer 21

The number of lines of force passing though a unit of area of material
Measured in Tesla’s
Newton per amp meter

Question 22

Why does increasing the current increase the force ?

motor effect

Answer 22

1. Magnetic field lines exist around a wire with a current

2. The larger the current the greater magnetic fie,s strength in the interaction between the wire and permanent magnet

Question 23

What is the generator effect (electromagnetic induction)?

Answer 23

When a conductor cuts the magnetic field lines of a magnet, a potential difference is induced across the ends of the conductor

Question 24

Describe the generator effect:

Answer 24

🟣wire with no current , within a magnetic field is experiencing a force
🟣this force is perpendicular to the direction of magnetic field
🟣as the wire cuts field lines, electrons are accelerated inducing a p.d
🟣this creates a current

Question 25

What happens when the motor and generator effect take place together?

Answer 25

The force and current produced by the motor effect counteracts the generator effect.(law of conservation of energy)

Question 26

State Lenz’s Law

Answer 26

The direction of the induced p.d is such that it opposes the change producing it

Question 27

How do you increase the induced p.d of an alternator?

Answer 27

🟣rotate coil faster (more field lines cut per second)
🟣stronger magnetic field (field lines closer together, so more cut)
🟣more coils
* doubling frequency

Question 28

What are transformers?

Answer 28

Devices that use a.c in the primary circuit to induce an a.c in the secondary current

Question 29

How do transformers work?

Answer 29

Question 30

Describe the difference between step up and step down transformers

Answer 30

Question 31

What is the normal line , of a wave diagram ?

Answer 31

The mean position of the particle

Question 32

What is the amplitude of a wave diagram ?

Answer 32

The maximum displacement of the particle from it’s mean position

Question 33

Describe the general specifics of electromagnetic radiation:

Answer 33

🟣transverse waves (light waves )
🟣do not require a medium to travel
🟣produced by vibrating ,charged particles

Question 34

What are the differences between electromagnetic waves and sound waves ?

Answer 34

Question 35

Describe UV waves

Answer 35

Very very slightly ionising m could possible cause cancer .
Moderately penetrate the earth’s atmosphere, but not the skin.

Question 36

What is activity?

Answer 36

The number of nuclei that decay per second

Question 37

How do you plot activity?

Answer 37

Divide mass by 2 , then plot this point .
Divide the new mass by 2 and then plot this point