P9 - Motion

Question 1

What is speed? What it’s unit?

Answer 1

distance travelled in a given time (m/s)

Question 2

What type of quanity is distance? What does this distance does not have?

Answer 2

scalar - no direction

Question 3

What is a scalar quantity?

Answer 3

has magnitude, no direction

Question 4

What is a vector quantity?

Answer 4

has magnitude & direction

Question 5

What is acceleration? What its unit?

Answer 5

change in veloc. over period of time - m/s squared

Question 6

What type of quantity is speed?

Answer 6

scalar

Question 7

What type of quantity is velocity?

Answer 7

vector

Question 8

On a distance-time graph, if the gradient is not constant & getting steeper, what does this mean for the vehicle?

Answer 8

accelerating

Question 9

On a distance-time graph, if the gradient is constant, what does this mean for the vehicle?

Answer 9

travelling @ constant speed

Question 10

On a distance-time graph, if the line is flat, what does this mean for the vehicle?

Answer 10

stationary

Question 11

On a distance-time graph, if the gradient is not constant & getting less steep, what does this mean for the vehicle?

Answer 11

deccelerating

Question 12

On a velocity-time graph, if the gradient is constant, what does this mean for the vehicle?

Answer 12

constant acceler.

Question 13

On a velocity-time graph, if the gradient is not constant & the line is getting steeper, what does this mean for the vehicle?

Answer 13

rate of acceler. ↑

Question 14

How do you calculate distance on a velocity-time graph?

Answer 14

calc. area under graph

Question 15

Define inertia.

Answer 15

how difficult it is to change an object’s motion

Question 16

Define inertial mass.

Answer 16

measure of how difficult it is to change the velocity of an object

Question 17

Which equation calculates (inertial) mass?

Answer 17

m=F/a

Question 18

What is only force acting on a skydiver when they first jump out of a plane?

Answer 18

weight

Question 19

Why is x force the only force acting on the skydiver when they jump out of a plane?

Answer 19

bc gravity - gravity will not change during skydiver’s fall

Question 20

Why do skydiver’s accelerate downwards?

Answer 20

bc weight> air resistance = resultant force acting ↓

Question 21

What opposing force does the skydiver experience as they continue to fall? What direction is the opposing force acting in?

Answer 21

air resistance acting ↑

Question 22

Even with air resistance, why does the skydiver continue to accelerate towards the ground?

Answer 22

weight still > air resistance

Question 23

What increases as the skydiver’s acceleration increases?

Answer 23

air resistance

Question 24

What does the air resistance eventually do to the weight? What does this mean?

Answer 24

become equal to weight -> no resultant force & velocity stays constant

Question 25

What is it called when there is no resultant force & velocity stays constant?

Answer 25

terminal velocity

Question 26

At what point does the skydiver open their parachute?

Answer 26

terminal velocity

Question 27

Why does opening the parachute mean that the skydiver doesn't die?

Answer 27

surface area ↑ = air resistance ↑

Question 28

What does the parachute mean for the weight? What does this result in?

Answer 28

air resistance > weight -> resultant force acting upwards & skydiver deccelerates

Question 29

What happens to the air resistance when the skydiver deccelerates?

Answer 29

air resistance ↓ -> air resistance = weight & resultant force = zero

Question 30

Even with air resistance, why does the skydiver continue to accelerate towards the ground?

Answer 30

weight still > air resistance