Cognito

Question 1

What is newtons 1st law

Answer 1

A resultant force is required to change the motion of an object

Question 2

What is newton second law

Answer 2

The acceleration of an object is proportional to the resultant force acting on it

And inversely, proportional to the object mass

Question 4

What is electromagnetism?

Answer 4

An electrical current flows through a wire a magnetic field is produced

Question 5

A current carrying wire how could you change the direction of the magnetic field?

Answer 5

Change the direction of the current

Question 6

What is a solenoids?

Answer 6

A coil of wire with a strong uniform magnetic field inside it

Question 7

What is an electromagnet

Answer 7

An electromagnet is a solenoid with an iron core inside
The magnetic field can be turned on or off by turning the circuit on and off

Question 8

Give 4 ways to increase the strength of a solenoid

Answer 8

Increase the current

Increase the number of turns in the solenoids bro keep in the length of the same

Reduce the length of the solenoid, while keeping the number of turns the same

Add a soft iron core

Question 9

What Is the motor effect

Answer 9

When A conductor carrying a current is placed in a magnetic field, the magnet producing the field, and the conductor will exert a force on each other.

Question 10

Larger force when wire carrying current

Answer 10

To the full force, a current carrying wire must be placed perpendicular to the magnetic field

Question 11

Give 4 ways to increase the strength of the motor effect

Answer 11

Increase the current

Use a coil of wire with multiple turns

Add a soft iron core

Use strong magnets

Question 12

What is a moment

Answer 12

Is the rotational or turning effect of a force

Question 13

What is a lever?

Answer 13

A device that increases the size of a force acting on an object
In order to make the object earn more easily
Leavers can be used to help us move all the things more easily

Question 15

How does a lever work

Answer 15

Transmitting the turning affect of a force, effectively multiply the force that gets applied to the object

Question 16

What are gears and how do they work

Answer 16

the teeth of different gears interlock, so that turning one causes another to turn
in the opposite direction
They are used to transmit the rotational affect of a force from one place to another

Question 17

Large or small gears rotate more quickly

Answer 17

Small gears

Question 18

Which 3 factor determine the pressure exerted by liquid

Answer 18

The depth .greater depth,more pressure
The density of the liquid-more dense liquid exter greater pressure
The gravitational field strength

Question 19

What is upthrust

Answer 19

A force that pushes up was on an object submerged in a fluid

Question 20

What determines whether an object in a liquid will float or sink?

Answer 20

If the way of the object is greater, it will sink

If the upthrust from the water is greater than the weight of the object, it will float

If the object is more dense than the water, it will sink

Question 21

What is the atmosphere

Answer 21

Layer of gas that surrounds the earth

Question 22

What is atmospheric pressure?

Answer 22

The total force of all the air particles constantly colliding with everything from all sides

Question 23

Why does atmospheric pressure decrease with altitude?

Answer 23

Pulling force from the gravitational field of a becomes weaker as altitude increases

So gas particles spread further part in the atmosphere becomes less dense

Question 24

What is terminal velocity?

Answer 24

The maximum velocity attainable by an object as it falls through a liquid

Question 25

What causes air resistance

Answer 25

Moving objects collide in particles in the air

Question 26

Explain why car crashes can cause injury to the passenger

Answer 26

The car on the passenger decelerate rapidly The experience large forces, because of the very fast change in momentum-and these large forces can cause injuries

Question 27

How do seatbelt work?

Answer 27

Stop you flying out of your seat during a car crash Buy stretching a little bit, they increase the time taken for the bodies momentum to reach zero, and so reduce the forces on acting on the body

Question 28

How do Air bags work?

Answer 28

Provide a soft surface to collide with you in a car crash By being flexible, the increase the time taken for the bodies momentum to reach zero, and so reduce the forces acting on the body

Question 29

How do crumple zones work

Answer 29

Areas of a vehicle that are designed to crumple in a controlled way during a collision Buy crumpling overtime, they increase the time taken for the passengers momentum to reach zero, and so reduce the forces acting on the bodies of the people in the car

Question 30

What Is refraction

Answer 30

Change in direction of a wave as it passes from one medium to another It is caused by the waves change in speed as the density of the meeting it is passing through changes

Question 31

Why can you see all the colours of the rainbow as white light passes through a prism?

Answer 31

White lights contains all the different wavelength of visible light As the light passes through the prism, the waves of different wavelength, slow down and get refracted to different degrees Which causes them to effectively spread out, allowing you to see all the different colours

Question 32

What does transparent mean?

Answer 32

Let’s all light through

Question 33

What does translucent mean?

Answer 33

Lets some light through

Question 34

What does opaque mean?

Answer 34

Let no light through

Question 35

Why do objects appear a certain colour?

Answer 35

Colour depends on the wavelength of light that it reflects For translucent objects, it also depends on which colour they transmit

Question 36

What is a perfect black body

Answer 36

Absorbs all of the radiation Does not reflect or transmit any radiation

Question 37

Is a black body a good or a bad emmiters of radiation

Answer 37

Best possible emitter

Question 38

How does the temperature of an object affect the wavelength of radiation it emits

Answer 38

Temperature increases, the wavelength of radiation emitted by the object decreases

Question 39

What does intensity mean in terms of infrared radiation?

Answer 39

Intensity is a measure of the power of the radiation, per unit area So high intensity means more radiation is emitted

Question 40

How does the frequency of a sound wave affect how it sounds?

Answer 40

The higher the frequency, the higher the pitch

Question 41

How does the amplitude of a sound wave affect how it sounds?

Answer 41

Higher the amplitude, the louder, the sound?

Question 42

How can ultrasound waves be used to detect the thickness of different mediums within an object?

Answer 42

Ultrasound reflects off off the boundaries between mediums of different densities The wave speed of the time it takes to bounce back to the receiver can be used to calculate the thickness of each medium

Question 43

What is Sonar

Answer 43

Technique that uses ultrasound wave to navigate, measure distances, communicate, and detect objects

Question 44

How can Sona be used to calculate the distance between a submarine and the seafloor?

Answer 44

Submarine can emit an ultrasound wave and measure the time it takes to return It can then use the speed of the wave and time taken to calculate distance

Question 45

What is a seismic wave?

Answer 45

Waves travel through the Earth

Question 46

P, waves, transverse, or longitudinal

Answer 46

Longitudinal