Unit 1 - Our Dynamic Universe (Part 1)

Question 1

what is a vector quantity?

Answer 1

magnitude and direction

Question 2

what is a scalar quantity?

Answer 2

no direction just size

Question 3

define velocity

Answer 3

the rate of change of displacement (displacement covered in a certain time)

Question 4

define acceleration

Answer 4

the rate of change of velocity (change of velocity in a certain time)

Question 5

what experiments do you use to find velocity and acceleration?

Answer 5

Measure velocity using one light gate, measure acceleration using two light gates

Question 6

Acceleration is …. proportional to force

Answer 6

Acceleration directly proportional to force - acceleration of any object in same direction as unbalanced force acting on it

Question 7

REVISE GRAPH OF MOTION - JUST FOR 5 MINUTES!

Answer 7

DONT SKIP YOU KNOW YOU DONT UNDERSTAND IT THAT IS WHY YOU HAVENT DONE ANY CUE CARDS FOR IT!!!!!

Question 8

define projectile motion

Answer 8

object projected horizontally or at an angle

Question 9

what is the projectile motion made up of?

Answer 9

constant horizontal velocity v=s/t and constant vertical acceleration (use SUVAT)

Question 10

define balanced forces

Answer 10

Forces equal in size, opposite in direction

Question 11

state newton’s first law of motion

Answer 11

an object will remain at rest or will remain at constant velocity unless acted upon by an unbalanced force

Question 12

what is friction

Answer 12

a resistive force that increases with velocity and always acts against the against the direction of motion

Question 13

define unbalanced forces

Answer 13

opposite in direction, unequal in size - causes acceleration

Question 14

what is weight?

Answer 14

a force caused by the presence of a mass in a gravitational field - measured in newtons (N)

Question 15

define Gravitational field strength

Answer 15

the force per unit mass

Question 16

state newtons second law of motion

Answer 16

the acceleration of an object varies directly with the unbalanced force and inversely with mass - F=ma - where F is equal to the unbalanced force which is calculated first.

Question 17

in a lift when will the the reading on some scales be heavier?

Answer 17

accelerating upwards, decelerating downwards

Question 18

in a lift when will the the reading on some scales be normal?

Answer 18

at rest or at constant speed

Question 19

in a lift when will the the reading on some scales be lighter?

Answer 19

decelerating upwards, accelerating downwards

Question 20

define power

Answer 20

the rate at which energy is transferred, measured in watts (w)

Question 21

what is 1 watt equal to?

Answer 21

1 joule per second

Question 22

state the law of conservation of energy

Answer 22

energy is never created nor destroyed - changed from one form into another

Question 23

state newtons third law of motion

Answer 23

if A exerts a force on B, then B exerts an equal but opposite force on A - forces exist in pairs that are equal in size but opposite in direction both occuring at the same time

Question 24

what is terminal velocity?

Answer 24

constant speed reached when air resistance balances weight

Question 25

what is momentum?

Answer 25

mxv - Greater mass, greater momentum - large amount of force to get moving and bring to rest

Question 26

what is the Law of conservation of linear motion/momentum?

Answer 26

total momentum before an interaction is equal to the total momentum after an interaction, in the absence of external forces

Question 27

what is the difference between and elastic and inelastic collision?

Answer 27

Energy conserved, Ek before = Ek after - elastic collision

energy not conserved = inelastic collision

Question 28

what is impulse (ft)?

Answer 28

change in momentum

Question 29

how to you find impulse from a graph?

Answer 29

area under force-time graph