Kinematics

Question 1

Is distance a scalar or vector quantity?

Answer 1

Scalar.

Question 2

Is displacement a scalar or vector quantity?

Answer 2

Vector.

Question 3

When a person throws a ball up in the air is the displacement positive or negative?

Answer 3

Positive displacement upwards.

Question 4

Why is that positive displacement is upwards and negative displacement is downwards?

Answer 4

Because displacement is a vector quantity.

Question 5

If a person completed a circular walk that was 20km in 5hrs what would their displacement and distance be?

Answer 5

Displacement = 0km
Distance = 20km

Question 6

What would their average speed and velocity be for the 20km circular walk in 5hrs?

Answer 6

Average:
Speed = 20/5
            = 4kmhr^-1
Velocity = 0/5
               = 0kmhr^-1

Question 7

Define speed.

Answer 7

The rate of change of distance with respect to time.

Question 8

Define displacement.

Answer 8

The shortest distance between two points on the line of travel independent of path.

Question 9

Define velocity.

Answer 9

The rate of change of displacement.

Question 10

Define Instantaneous speed.

Answer 10

The rate of change of distance at a given instant.

Question 11

Define acceleration.

Answer 11

The rate of change of velcoity per unit time.

Question 12

What is the formula to calcuate acceleration?

Answer 12

v-u/t where v = final velcoty, u = initital velocity and t = time.

Question 13

Give two examples when is an object accelerating.

Answer 13

1) When it’s speed is increasing.

2) When it is changing direction.

Question 14

Give an example when an object is deceerating.

Answer 14

When it’s speed is decreasing.

Question 15

Define rate of change.

Answer 15

Change in a quanitity relative to another quanitity, usually time.

Question 16

What does the gradient of a distance-time graph represent?

Answer 16

The velocity of an object at a specific time.

Question 17

What does the area under a speed-time graph represent?

Answer 17

The distance travelled in that time at that speed.

Question 18

What deos the gradient of a speed-time graph represnt?

Answer 18

The magnitude of the acceleration.

Question 19

Define average speed?

Answer 19

The total distance travelled divided by the time taken to travel that distance.

Question 20

What does the gradient of a displacement-time graph represent?

Answer 20

The velocity.

Question 21

What does the area under a velocity-time graph represent?

Answer 21

The displacement.

Question 22

What does the gradient of a velocity-time graph represent?

Answer 22

The acceleration.

Question 23

What does a negative gradient on a velocity-time graph represent?

Answer 23

The object is decelerating.

Question 24

What does a positive gradient on a velocity-time graph represent?

Answer 24

The velocity of an object is increasing.

Question 25

Sketch a displacement-time graph and velocity-time graph for displacement zero.

Answer 25

Look at notes!

Question 26

Sketch a s/t, v/t and a/t graph to represent a falling object.

Answer 26

Look at notes!

Question 27

Define average velocity.

Answer 27

The total displacement divided by the time taken to achieve that displacement.

Question 28

Define uniform motion.

Answer 28

Motion with no change in velocity, i.e zero acceleration.

Question 29

What does a straight line on a displacement-time graph represent?

Answer 29

Uniform velocity.

Question 30

How would you calculate the instantaneous velocity on a displacement-time graph?

Answer 30

Draw a tangent to the point and calculate the gradient of the tangent.

Question 31

What does a negative gradient represent?

Answer 31

Motion in the opposite direction.