Physics

Question 1

Momentum

Answer 1

The product of an object’s mass and its velocity

Question 2

Linear momentum

Answer 2

A vector quantity with the same direction as the velocity of the object

Question 3

Newton’s 2nd law (momentum)
Fnet◇t =◇p

Answer 3

The net (or resultant) 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 4

Impulse
Fnet◇t=◇p

Answer 4

The product of the resultant/net force acting on an object and the time the net force acts on the object

Question 5

System

Answer 5

A set number of objects and their interaction with each other.

Question 6

Internal forces

Answer 6

Forces exerted by the particle in the system on one another

Question 7

External forces

Answer 7

Forces exerted from outside the system on the particles of the system.

Question 8

Isolated system

Answer 8

A system on which the net external force is zero. Excluding gravitational force

Question 9

Principle of conversation of linear momentum

Answer 9

The total linear momentum of an isolated system remains constant (is conserved)

Question 10

The doppler effect

Answer 10

The change in frequency (or pitch) of the sound detected by a listener, because the sound source and the listener have different velocities relative to the medium of sound propagation.

Question 11

Ohm’s Law R= V÷I

Answer 11

The potential difference across a conductor is directly proportional to the current in the conductor at a constant temperature.

Question 12

EMF

Answer 12

The maximum energy provided by a battery per unit charge passing through it.

Question 13

Work function

Answer 13

The minimum energy that an electron in the metal needs to be emitted from the metal surface.

Question 14

Threshold frequency

Answer 14

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

Question 15

Photoelectric effect

Answer 15

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

Question 16

Coulomb’s law F=KQQ÷r²

Answer 16

The magnitude of the electrostatic force exerted by one point charge on another point charge is directly proportional to the product of the magnitude ls of the charges and inversely proportional to the square of the distance between them.

Question 17

Electric field

Answer 17

A region of space in which an electric charge experiences a force.

Question 18

Electric field at a point E= F÷q

Answer 18

The electric field at a point is the electrostatic force experienced per unit positive charge placed at that point.
Work is done by a force not against a force.

Question 19

Work done on an object by a constant force

Answer 19

F◇xcos○, where F is the magnitude of the force, ◇x the magnitude of the displacement and ○ the angle between the force and the displacement.
Work is done by a force not against a force.

Question 20

Work-energy theorm
Wnet=◇k

Answer 20

The work done on an object by a net force is equal to the change in the object’s kinetic energy.

Question 21

Non conservative force

Conservative force

Answer 21

A force for which the work done in moving an object between two points

Depends on the path taken

Is independent of the path taken

Question 22

Principle of conversation of mechanical energy

Answer 22

The total mechanical energy (sum of gravitational potential energy and kinetic energy) in an isolated system remains constant.

Question 23

Power P= W÷◇t

Answer 23

Rate at which work is done or energy is expanded(transferred)

Question 24

Free fall

Answer 24

Motion during which the only force acting on an object is the gravitational force

Question 25

Projectile

Answer 25

An object which has been given an initial velocity and then it moves under the influence of gravitational force only.

Question 26

Normal force

Answer 26

The force or the component of a force which a surface exerts on an object with which it is in contact, and which is perpendicular to the surface.

Question 27

Frictional force

Answer 27

The force that opposes the motion of an object and which acts parallel to the surface.

Question 28

Static frictional force

Answer 28

The force that opposes the tendency of motion of a stationary object relative to a surface.

Question 29

Kinetic frictional force

Answer 29

The force that opposes the motion of a moving object relative to a surface.

Question 30

Newton's 1st law

Answer 30

A body will remain in its state of rest or motion at constant velocity unless a non-zero resultant/net force acts on it.

Question 31

Newton's 2nd law Fnet=ma

Answer 31

When a net force acts on an object, the object will accelerate in the direction of the force, and the acceleration is directly proportional to the force and inversely proportional to the mass of the object.

Question 32

Newton's 3rd law

Answer 32

When object A exerts a force on object B, object B simultaneously exerts on oppositely directed force of equal magnitude on object A.

Question 33

Newton's law of universal gravitation F= Gmm÷r²

Answer 33

Each body in the universe attracts every other body which 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 34

Weight

Answer 34

The gravitational force the earth exerts on any object on or near its surface

Question 35

rms Potential difference

Answer 35

The AC potential difference which dissipates/produces the same amount of energy as an equivalent DC potential difference.

Question 36

rms Current

Answer 36

The alternating current which dissipates/produces the same amount of energy as an equivalent firect cutrent (DC)