Physics test 9th grade #1

Question 1

Speed formula

Answer 1

distance/time

Question 2

Speed definition

Answer 2

The speed of an object is given by the ratio between distance travelled and time taken

Question 3

Are average speed and actual speed the same

Answer 3

No, actual speed changes while average speed does not

Question 4

how is speed measured

Answer 4

Km/h
m/s
mph

Question 5

What is the magic triangle

Answer 5

Distance/speed x time

Question 6

How fast

Answer 6

speed - distance/time

Question 7

how far

Answer 7

distance - speed x times

Question 8

how long

Answer 8

time - distance/speed

Question 9

difference between speed and velocity

Answer 9

speed is about movement in general while velocity is speed with direction

Question 10

Vector

Answer 10

A quantity that has value (magnitude) as well as a direction. Number + Unit + direction

Question 11

Scalar

Answer 11

A quantity that is represented by a simple numerical value. Number + unit

Question 12

is velocity is vector or scalar

Answer 12

vector

Question 13

Is speed a vector or scalar

Answer 13

Scalar

Question 14

What symbol is used to represent velocity?

Answer 14

an arrow.

Question 15

is weight a scalar is vector or scalar

Answer 15

weight is a vector

Question 16

is acceleration a vector or scalar

Answer 16

vector

Question 17

What do the details that the symbol that represents velocity tell us

Answer 17

Length = magnitude/size
Direction = direction

Question 18

What is acceleration

Answer 18

when there is a change in velocity:
- speed increases (positive acceleration)
- speed decreases (negative acceleration)
- change in direction

Question 19

When acceleration occur

Answer 19

when there is a change of speed, direction, or both

Question 20

acceleration formula

Answer 20

a = (v - u) / t
a = acceleration
u = initial speed
t = time

Question 21

When speed increases it is called

Answer 21

positive acceleration

Question 22

when speed decreases its called

Answer 22

negative acceleration

Question 23

In distance time graphs, whats on the x axis and whats on the y axis

Answer 23

distance is on the y axis, time is on the x

Question 24

In a distance time graph, a straight flat line represents…

Answer 24

no movement (v=0)

Question 25

In a distance time graph, positive constant speed is show as...

Answer 25

a straight line going vertically up

Question 26

In a distance time graph, if there are two lines, how do you determine which one is greater

Answer 26

look at the distance both lines are at at the same time to determine which one is greater

Question 27

In a distance time graph, how do u represent negative constant speed

Answer 27

a straight line going down

Question 28

How do you show acceleration on a distance time graph

Answer 28

it is a slope. Negative goes down and positive goes up

Question 29

What is the formula to find the slope

Answer 29

rise/run

Question 30

In a distance time graph, are the slope and speed related

Answer 30

yes, mathematically speaking, the slope is the speed because rise/run = distance/time

Question 31

In speed time graphs, what does no movement look like

Answer 31

a straight line on the x axis

Question 32

In speed time graphs, what does constant positive speed look like

Answer 32

A straight line not on the x axis

Question 33

In speed time graphs, how is negative speed represented

Answer 33

by a line under the x axis

Question 34

In speed time graphs, what does a diagonal line going up represent

Answer 34

positive acceleration

Question 35

In speed time graphs, what does a diagonal line going down represent

Answer 35

negative acceleration

Question 36

In speed time graphs, how to you determine which line is greater

Answer 36

whichever is higher up

Question 37

In speed time graphs, what is the slope equivalent to

Answer 37

acceleration. slope = rise/run = speed/time acceleration = speed/time = rise/run

Question 38

How do you find the distance on speed time graphs?

Answer 38

Find the area of the shape made by the line. For a rectangle it would be speed x time. For a triangle it would be 1/2 speed x time

Question 39

What happens to an object after its released

Answer 39

it falls with increasing speed which is acceleration

Question 40

Why do objects fall

Answer 40

gravity

Question 41

when do heavier objects fall faster than lighter ones

Answer 41

when theres air resistance

Question 42

what 2 forces act upon an object

Answer 42

gravity and air resistance

Question 43

what affects air resistance

Answer 43

the shape of the object

Question 44

If there was no air resistance, how would this affect objects

Answer 44

all objects would fall with the same acceleration. This is called the acceleration of free fall or g

Question 45

the speed at which an object falls in a vacuum depends on...

Answer 45

the local gravitational field strength

Question 46

What does g stand for

Answer 46

the acceleration of free fall

Question 47

What is the acceleration of free fall

Answer 47

The acceleration of objects falling without air resistance

Question 48

What is the g on Earth

Answer 48

approximately 10

Question 49

Will an object fall faster on the moon or earth (with no air resistance)

Answer 49

The earth because it has a stronger gravitational field than the moon does

Question 50

If an object is moving under free fall, its velocity is given by

Answer 50

v = g x t or v = 10t

Question 51

How do you find the distance of an object that is accelerating free falling

Answer 51

5t^2 where t = time This is because normally you would do 1/2 speed x time. Speed is 10t. so it is 1/2 10t x t. This can be simplified to 5t^2

Question 52

What is free fall

Answer 52

falling because of the force of gravity without air resistance

Question 53

if a rock fell for 3 seconds what would be its velocity and distance travelled

Answer 53

v = 30 d = 45m

Question 54

what is free fall?

Answer 54

anything that is released into the air. For example, even throwing something up is considered free fall

Question 55

How do you find velocity and distance when an object is launched straight up in the air (free fall)

Answer 55

as the object moves up, the velocity decreases by ten. as it goes down, it repeats the sequence in reverse (increases by 10)

Question 56

If an arrow was shot straight up for two seconds at an initial speed of 20, what is its velocity every second

Answer 56

t = 0 v = 20 t = 1 v = 10 t = 2 v = 0 t = 3 v = 10 t = 4 v = 20

Question 57

How do you find the distance of an object in free fall when its shot up straight in the air

Answer 57

the total time squared times 5. For example, 4 x 4 = 16. 16 x 5 = 80

Question 58

Newtons first law

Answer 58

an object in motion will stay in motion unless another force acts upon it

Question 59

Newtons third law

Answer 59

for every action, there is an equal and opposite reaction

Question 60

force formula

Answer 60

force = acceleration x mass

Question 61

how to draw a force diagram

Answer 61

four arrows showing four forces - earth pushing up - gravity - friction/ air resistance - momentum from vehicle resultant force: bigger force - smaller force

Question 62

mass vs weight

Answer 62

Mass is the total amount of matter, or "stuff," in an object. Weight is the force of gravity on an object. w = mass x 10