Test 3 completed

Question 1

G.P.E formula?

Answer 1

change in potential energy= mass x gravity x change in height

Question 2

Describe how to use a stop-watch to determine the time period of the pendulum.

Answer 2

-(use stop-watch to) time oscillations
-(use of fiduciary) aid to determine a complete cycle
-(use of) multiple oscillations AND division (to determine period)

Question 3

Which energies do not come from the Sun?

Answer 3

Geothermal, nuclear and tidal powers

Question 4

Kinetic energy equation?

Answer 4

Ek=1/2mv^2

Question 5

State and explain the main process by which thermal energy is transferred to the worker.

Answer 5

Thermal energy is transferred by thermal radiation. Infrared travels through the air and is absorbed by the worker.

Question 6

State and explain the main process by which thermal energy is transferred from the outer
surface of the solid metal rollers to their interior.

Answer 6

Thermal energy is transferred by conduction. The electrons are free to move and move from the surface to the interior of the roller.

Question 7

State the reasons why the image IY is virtual.

Answer 7

Image cannot be formed on a screen. The rays do not converge. The object is closer than one focal length.

Question 8

State the direction of the force that the N pole of magnet 2 exerts on the N pole of magnet 1. Justify.

Answer 8

In the direction of magnetic field.
Opposite charges attract.

Question 9

Diode symbol

Answer 9

Triangle and line with wire

Question 10

Explain whether this method of generation of electrical power is renewable.

Answer 10

Cannot be used up, will always be there

Question 11

Calculating thermal energy.

Answer 11

specific heat capacity equation

Question 12

The light intensity at the circuit increases from dark to bright.
State any effect on the resistance of component Y.

Answer 12

Resistance decreases, so voltage decreases.

Question 13

Calculate the number of electrons that pass through the resistor each second.

Answer 13

n= I/Q

Question 14

The light intensity at the circuit increases from dark to bright.

State any effect on the resistance of component Y, the LDR.
There is another resistor in series with Y.

State and explain any effect on the reading of the voltmeter.

Answer 14

Resistance across R decreases, so current increases and voltage decreases.
Overall resistance in the circuit decreases.