Physics

Question 1

Speed =

Answer 1

Distance/time

Question 2

Average acceleration=

Answer 2

Change in velocity/time taken

Question 3

2nd law of motion

Answer 3

F=ma

Question 4

3rd law of motion

Answer 4

Whenever an object exerts a force on an object there is an equal and opposite reaction

Question 5

Electricity is a flow of

Answer 5

Elections

Question 6

Flow of electric current depends on

Answer 6

Potential difference and current and resistance

Question 7

Voltmeter measures

Answer 7

Potential difference in volts

Question 8

Circuit flowing is measured in

Answer 8

Amps using a ammeter

Question 9

Resistance is measured in

Answer 9

Ohms

Question 10

As volt increase the current

Answer 10

Increase

Question 11

Electricity is produced when a conductor is connected to the positive and negative terminators of a power source like battery and electron flow to the positive/negative terminal

Answer 11

Positive terminal

Question 12

As voltage increase, current and resistance :

Answer 12

Increase

Question 13

Light travels

Answer 13

300,000 km/s

Question 14

What colour is an object if they reflect, absorb all light?

Answer 14

Black or white

Question 15

Angle of reflection:

Answer 15

Angle of incidence, angle of reflection, critical point, total internal refraction, normal

Question 16

Concave makes things

Answer 16

Focused on a single point, all light is converged to be concentrated to a sharp image

Question 17

Convex makes image

Answer 17

More of image is seen

Question 18

What is refraction?

Answer 18

The change of direction when light enters from one medium to another

Question 19

Law of reflection states that:

Answer 19

Light waves bounce back off the surface at the same angle that they strike the surface.
Angle of incident = angle of reflection

Question 20

Refraction is bending of

Answer 20

Light

Question 21

Electromagnetic spectrum allows us to

Answer 21

Communication, exploration universe and medicine

Question 22

Optical fibres make use of visible light to transmit messages over long distance why is it better?

Answer 22

Cheaper, little energy, smaller tubes, faster

Question 23

Optical fibre:

Answer 23

Thin, glass core, protective jacket, total internal reflection, more info than copper wires

Question 24

Isotopes have same number of protons but different number of

Answer 24

Neutrons

Question 25

Alpha particles can be stopped by paper t/f?

Answer 25

True

Question 26

Nuclear reactions found in sun are

Answer 26

Nuclear fusion

Question 27

Nuclear fusion:

Answer 27

Fusing two lighter atoms to a heavier one Occurs naturally in stars High density and temp Extremely high energy to overcome electrostatic repulsion Hydrogen bomb

Question 28

Nuclear fission:

Answer 28

A neutron strikes a uranium nucleus which break into fragments. Free neutron stile other uranium nucleus creating a chain reaction Doesn't occur naturally Little energy Atomic bomb

Question 29

Half life

Answer 29

Time taken for half of the nuclei to decay

Question 30

Nebula

Answer 30

Large clouds of solar gases and stellar dust

Question 31

Protostar

Answer 31

When cloud of gas cool and collapses begins to heat up

Question 32

Quasars

Answer 32

Remote, dense, radio wave emiting dead star, light emiting

Question 33

Inertia

Answer 33

The tendency of a body to maintain its state of rest or uniform motion in straight line until acted upon an opposite force

Question 34

Neutralisation define

Answer 34

To stop something from having an effect

Question 35

Decplacement reactions take place when

Answer 35

one metal pushes a compound and take its place

Question 36

When metal reacts with acid:

Answer 36

Metal+hydrochloric acid > salt + hydrogen

Question 37

In order for metal to react with acid it must be BEFORE OR AFTER hydrogen

Answer 37

Before

Question 38

Types of galaxies

Answer 38

Elliptical Spiral Irregular Barred spiral