Definitions

Question 1

define force

Answer 1

the rate of change of momentum

Question 2

define gravitational potential energy

Answer 2

energy possessed by a body in a gravitational field

Question 3

define kinetic energy

Answer 3

energy posessed by a body in motion

Question 4

define stress

Answer 4

the force applied per unit cross-secctional area of the wire

Question 5

define acceleration

Answer 5

the rate of change of veloctiy

Question 6

define strain

Answer 6

the fractional increase in the original legth of the wire

strain = l/x

Question 7

define elastic potential energy

Answer 7

the energy stored in a stretched or compressed material

Question 8

state newtons first law

Answer 8

a body will remain at rest or in motion at a constant speed unless an external force acts on it

Question 9

state newtons second law

Answer 9

the resultant force is equal to the rate of change of momentum

Question 10

state newtons third law

Answer 10

if body A exerts a force on body B body B will exert an equal but opposite force on body A

Question 11

define displacement of a wave

Answer 11

its the distance of a point on the wave from its equilibrium position

Question 12

define amplitude

Answer 12

is is the maximum displacement from equilibrium

Question 13

define wavelength

Answer 13

the distance travelled by a wave in one complete oscillation

Question 14

define period

Answer 14

time taken to complete one oscillation

Question 15

define frequency

Answer 15

the number of oscillations per unit time

Question 16

define phase difference

Answer 16

the amount by which one oscillation leads or lags behind another measured in degrees or radians

Question 17

define intensity of a wave

Answer 17

energy transfered per unti are at right angles to the wave velocity

Question 18

define current

Answer 18

rate of flow of charge

Question 19

defeine p.d

Answer 19

energy transfered per unit flow of charge flowing from one point to another

Question 20

define emf

Answer 20

energy provided by the cell or battery per coulumb of charge passing through it

Question 21

define emf

Answer 21

work done by source driving a unit charge around a complete circuit

Question 22

state the principle of conservation of momentum

Answer 22

within a closed, the total momentum in any direction is constant

Question 23

state kirchnoff’s first law

Answer 23

current into a junction is equal to current out of the junction

Question 24

state kirchnoff’s second law

Answer 24

the sum of electromotive forces in a closed circuit is equal to the sum of potential difference

Question 25

state hooke's law

Answer 25

f=kx

Question 26

define displacement

Answer 26

distance in a specified direction

Question 27

define displacement

Answer 27

distance in a specified direction

Question 28

define velocity

Answer 28

the rate of change of displacement

Question 29

define work done

Answer 29

the product of the force and the distance moved in the direction of the force

Question 30

define pressure

Answer 30

the normal force acting per unti cross sectional area

Question 31

define volume

Answer 31

the mass per unit volume of a substance

Question 32

define young modulus

Answer 32

ratio of stress to strain of a material

Question 33

state ohms law

Answer 33

for a conductor at a constant temperature, the current through it is proportional to potential difference across it

Question 34

define a progressive wave

Answer 34

a wave that has a net transfer of energy

Question 35

define a transverse wave

Answer 35

the oscillations are perpendicular to the direction of travel

Question 36

define a longitudinal wave

Answer 36

the oscillations are parallel to the directions of travel

Question 37

state the principle of moments

Answer 37

for a system in equilibrium the sum of the antclokwise moments in equal to the sum of clockwise moments

Question 38

state what is meant by coherent

Answer 38

constant phase difference

Question 39

state what is meant by monochromatic

Answer 39

single wavelengths

Question 40

state current in series and in parallel components

Answer 40

current is the same for components in series but is shared between components in parallel

Question 41

state voltage in series and in paralell components

Answer 41

voltage is shared between components in series and is the same for components in parallel

Question 42

high frequency= low frequency=

Answer 42

short wavelength long wavelength

Question 43

state the conditions for a stationary wave

Answer 43

waves need to: 1. have the same frequency and amplitude 2. be in opposite directions

Question 44

state archimedes principle

Answer 44

a bouyant force acts on a body at rest in a fluid upwards and it is equal to the weight displaed by the body in the fluid

Question 45

coplanar forces...

Answer 45

sum of F1 and F2 is equal to the frictional force

Question 46

what happens in an elastic collision

Answer 46

it is a non-stick collision kinetic energy is conserved

Question 47

what happenes in an inelastic collision

Answer 47

it is a stick collision kinetic energy is not conserved