combination

Question 1

acceleration formula

Answer 1

change in velocity/time

Question 2

gravitational field formula

Answer 2

W/m

Question 3

resultant force

Answer 3

sum of total forces acting on an object

Question 4

Newtons 1st law

Answer 4

an object either remains at rest or continues in a straight line at constant speed unless acted on by a resultant force

Question 5

springs constant formula

Answer 5

force per unit extension k=F/x

Question 6

limit of proportionality

Answer 6

the extension that Hookes law no longer applies to - the extension is no longer proportional to the force

Question 7

formula of force in relation to mass and acceleration

Answer 7

force = mass x acceleration

Question 8

describe an object in circular motion

Answer 8

1. speed increases as force increases, with mass and radius constant
2. radius decreases if force increases, with mass and speed constant
3. an increased mass requires an increased force to maintain radius and speed

Question 9

friction

Answer 9

force that opposes motion and causes heating when two objects are rubbed against each other

Question 10

moment of a force

Answer 10

measure of its turning effect

Question 11

when is an object in equilibrium

Answer 11

when the sum of all forces must be zero, when anticlockwise moments = clockwise moments

Question 12

torque/turning effect

Answer 12

a measure of the force that can cause an object to rotate about an axis

Question 13

centre of gravity

Answer 13

a point where the mass of the body is concentrated

Question 14

5 examples of energy stores

Answer 14

kinetic, GPE, chemcial, elastic, electrostatic

Question 15

how is energy transferred during events and processes (4 examples)

Answer 15

forces, electrical currents, heating, waves

Question 16

conduction

Answer 16

transfer of thermal energy by collisions of particles from hot regions to cold regions

Question 17

experiment to test conduction

Answer 17

the boiling water wax experiment thing

Question 18

why are metals good conductors

Answer 18

metals contain free electrons that can move anywhere in the lattice. these electrons gain heat energy in the hot regions and carries the energy to other parts of the lattice.

Question 19

convection

Answer 19

hot fluid particles expand and rise, whereas cold fluid particles shrink and sink.

Question 20

infrared radiation

Answer 20

transfer of thermal energy without a medium

Question 21

conservation of energy

Answer 21

energy can neither be created nor destroyed

Question 22

kinetic energy formula

Answer 22

1/2mv^2

Question 23

gravitational potential energy formula

Answer 23

m x g x h

Question 24

mechanical work done

Answer 24

the amount of force needed to move an object a certain distance

Question 25

what mechanical work done formula

Answer 25

W = Fd

Question 26

efficiency formula

Answer 26

useful energy ouput/total energy input x 100

or

useful power input/total power input x 100

Question 27

power

Answer 27

the rate of transfer of energy, P = W/t, P = ΔE/t

Question 28

pressure

Answer 28

force per unit area, P = F/A

Question 29

mechanical work done

Answer 29

force to move an object