Physics June P1

Question 1

Free fall

Answer 1

the motion of an object under the influence of gravity only

Question 2

projectile

Answer 2

n object launched with an initial velocity and upon which the only force action is the force of gravity

Question 3

when is no work done on an object

Answer 3

No displacement
force acts perpendicular to the displacement

Question 4

work energy theorem

Answer 4

the net work done on an objects equal to the change in the object’s kinetic energy

Question 5

power

Answer 5

the rate at which work is done (scalar quantity measured in watts)

Question 6

when do you use the principle of conservation of Emech

Answer 6

when there is no friction

Question 7

conservative force

Answer 7

a force for which the work done in moving an object between two points is independent of the path taken

Question 8

non conservative force

Answer 8

a force for which the work done in moving an object between two points depends on the path taken

Question 9

gravitation potential energy

Answer 9

energy an object has because of its position in the gravitational field relative to a reference point

Question 10

kinetic E

Answer 10

Energy an object has as a result of its motion

Question 11

mechanical E

Answer 11

sum of an object’s kinetic and potential E

Question 12

momentum

Answer 12

product of objects mass and velocity (p=mv)

Question 13

Newton’s 2nd law of motion in terms of momentum

Answer 13

the net force acting on an object is equal to the rate of change of momentum of the object in the direction of the net force

Question 14

impulse

Answer 14

product of net force and time

Question 15

isolated system

Answer 15

system on which the net external force is zero

Question 16

elastic collision

Answer 16

total kinetic E is conserved

Question 17

doppler effect

Answer 17

the apparent change in frequency of a sound detected by a listener as a result of the relative motion between the source of sound and the listener

Question 18

frequency

Answer 18

number of wave pulses per second

Question 19

period

Answer 19

time taken for one complete wave pulse

Question 20

wavelength

Answer 20

distance between two successive points in phase

Question 21

doppler effect uses

Answer 21

detect a foetal heartbeat
measure the rate of blood flow

Question 22

red shift

Answer 22

when a star moves away from the earth, the light waves behind the star increase, causing a shift of the light towards the red end of the spectrum

Question 23

weight

Answer 23

gravitational force exerted by the earth on an object or near its surface

Question 24

newton law of universal gravitation

Answer 24

each body in the universe attracts every other body with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centres

Question 25

potential difference

Answer 25

energy transferred per unit charge flowing between two points through a conductor (V=W/Q)

Question 26

emf

Answer 26

energy provided by a battery per unit charge flowing through the battery

Question 27

current strength

Answer 27

rate of flow of charge (I=Q/t)

Question 28

resistance

Answer 28

ratio between the pot. diff. across a resistor and the current in the resistor (R=V/I)

Question 29

one ohm

Answer 29

one volt per ampere

Question 30

ohm's law

Answer 30

pot. diff. across a conductor is directly proportional to the current in the conductor at constant temp

Question 31

series vs parallel

Answer 31

series divides V parallel divides I

Question 32

electric field

Answer 32

region of space in which an electric charge experiences a force

Question 33

electric field at a point

Answer 33

the electrostatic force experienced per unit positive point charge placed at that point

Question 34

principle of conservation of charge

Answer 34

the net charge of an isolated system remains constant during any physical process

Question 35

photoelectric effect

Answer 35

process whereby electrons are ejected from a metal surface when light of suitable frequency is incident on that surface

Question 36

photon

Answer 36

an energy packet of light

Question 37

Threshold frequency

Answer 37

minimum frequency of light needed to emit electrons from a certain metal surface

Question 38

threshold wavelength

Answer 38

maximum wavelength of light needed to emit electrons from a certain metal surface

Question 39

work function

Answer 39

the minimum energy that an electron of a particular metal needs to be emitted from the metal surface

Question 40

what nature of light does the photoelectric effect prove?

Answer 40

that light has a particle nature

Question 41

RMS voltage

Answer 41

the potential difference in an AC circuit that dissipates the same amount of energy as a DC circuit

Question 42

RMS current

Answer 42

the current in an AC circuit that dissipates the same amount of energy as a DC circuit

Question 43

explain electromagnetic induction by a generator

Answer 43

the armature causes a change in magnetic flux linked to the coil and this induce a current in the coil

Question 44

coulombs law

Answer 44

the magnitude of the electrostatic force of attraction or repulsion exerted by one point charge on another point charge is directly proportional to the magnitude of the product of their charges and inversely proportional to the square of the distance between their centres

Question 45

principle of conservation of charge

Answer 45

the net charge of an isolated system remains constant during any physical process