physics

Question 1

define normal force

Answer 1

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

Question 2

define frictional force

Answer 2

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

Question 3

define static frictional force

Answer 3

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

Question 4

define kinetic frictional force

Answer 4

the force that opposes thethe motion of moving object relative to the surface

Question 5

define newtons first law

Answer 5

a body will remain in its state of res or motion until a non zero resultant/net force is acted on it

Question 6

define newtons second law

Answer 6

when a resultant /net force is exerted on an object the object will accelerate in the direction of the force with an acceleration directly proportional to the force and inversely proportional to the mass of the object

Question 7

define newtons third law

Answer 7

when object A exerts a force on object B object B will exert an oppositly directed force of equal magnitude onto object A

Question 8

define newtons universal law of graitation

Answer 8

every particle attracts every other particle with a gravitational force that is directly proportional to the product of their masses and inversely propotionalto distance between their centres

Question 9

define weight

Answer 9

the gravitational force the earth exerts on an object on or near its surface w=mg

Question 10

define weightlessness

Answer 10

the sensation experienced when all contact forces have been removed

Question 11

define momentum

Answer 11

the product of an objects mass and velocity

Question 12

define linear momentum

Answer 12

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

Question 13

define newtons second law in terms of momentum

Answer 13

the net/resultant force of an object is equal to the rate of change of momentum of the object in the direction of the net force

Question 14

define impulse

Answer 14

the product of the net force acting on an object an the time in which the net force acts on the object

Question 15

define isolated system

Answer 15

a system in which the net external force is zero

Question 16

state the principal of conservation of linear momentum

Answer 16

the total linear momentum of an isolated remains constant

Question 17

define collision

Answer 17

a collision is an isolated event which two or more moving bodies exert a force on each other over a short time

Question 18

define a system

Answer 18

a collection of two or more objects that interect with each other

Question 19

define an elastic collision

Answer 19

kinetic energy in a system is conserved

Question 20

define inelastic collison

Answer 20

kinetic energy in a system is not conserved

Question 21

define work done

Answer 21

work done on an object by a constant force a Fxcos(angle) where F is the magnitude between the force x is the magnitude of the displacement and (angle) is the angle between the force and the displacement

Question 22

define work

Answer 22

is done when a force acts on an object and causes it to move in a direction parallel to the force

Question 23

define the work energ theorem

Answer 23

the work done on an object by a net force is equal to the change in the objects kinetic energy

Question 24

define connservative force

Answer 24

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

Question 25

define non conservative force

Answer 25

force for which the work done in moving an object between to points is dependent of the path taken

Question 26

examples of non conservative force

Answer 26

frictional force air resistance tension in a chord

Question 27

examples of conservative force

Answer 27

gravitational force elastic force in a spring electrostatic force

Question 28

state the principal of conservation of mechanical energy

Answer 28

the total mechanical energy of an isolated system remains constant

Question 29

define power

Answer 29

the rate at which work is done or energy is expended

Question 30

define doppler effect

Answer 30

percieved change in frequency or pitch of the sound detected by the listener because the sound source and the listener have different velocities reletive to the medium of sound propaganda

Question 31

define frequency

Answer 31

the number of waves that pass a point in one second

Question 32

define period

Answer 32

the time taken for one wave to occur

Question 33

define wavelength

Answer 33

the distance between two consecutive points in phase

Question 34

define soundwave

Answer 34

is emitted in all directions

Question 35

define projectile

Answer 35

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

Question 36

define free fall

Answer 36

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

Question 37

define terminal velocity

Answer 37

is the constant velocitiy that a free falling object eventyally reaches when the air resistance prevents further acceleration

Question 38

define ohms law

Answer 38

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

Question 39

define EMF

Answer 39

the amount of electrical energy supplied y the battery per coulomb at charge moved between its terminal

Question 39

define current

Answer 39

the rate of the flow of charge

Question 40

define coulombs law

Answer 40

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

Question 41

define electric fields

Answer 41

a reigion of space in which an electric charge experiences a force

Question 42

define terminal potential differnce

Answer 42

the potential difference across the terminals of a battery when there is a current in the circuit

Question 43

define resistance

Answer 43

the opposition of the flow of charge

Question 43

define potential difference

Answer 43

between two points in a circuit is the work done in moving unit charge (one coulomb) from one point to the other