Physics Test 1 (Heat Transfer)

Question 1

Which state has the highest density?

Answer 1

Solids

Question 2

Equation for density

Answer 2

D = M/V

Question 3

Density of Water

Answer 3

1g/cm^3

Question 4

What energy is released in a light bulb

Answer 4

Light & Heat

Question 5

Efficiency equation (Energy output)

Answer 5

Useful energy/Total energy
X 100

Question 6

Coal power station efficiency

Answer 6

35%

Question 7

LED Lights efficiency

Answer 7

90%

Question 8

Car engine efficiency

Answer 8

40%

Question 9

Name the 3 types of heat transfer

Answer 9

Conduction Convection Radiation

Question 10

Name a good conductor of heat

Answer 10

Metals e.g copper - because they have free electrons

Question 11

Name an insulator

Answer 11

Plastics - Don’t have free electrons

Question 12

How does conduction work?

Answer 12

Particles collide when vibrating and make other particles vibrate

Question 13

Where does conduction take place

Answer 13

Solids and liquids - mainly solids

Question 14

Where does convection take place

Answer 14

Liquids and gases

Question 15

How does convection work

Answer 15

When liquid/gas gets heated the particles get more energy and speed up, this makes them spread apart which gives the liquid/gas more volume, making it less dense. The less dense things rise and the denser things sink.

Question 16

Equation for mass

Answer 16

M = D x V

Question 17

Equation for volume

Answer 17

V = M/D

Question 18

What is thermal radiation

Answer 18

Heat waves coming off something and making other things hot - doesn’t need particles so can happen in a vacuum e.g. space

Question 19

Where does thermal radiation occur

Answer 19

Solids liquids gases