Motion

Question 1

What is the formula for average speed

Answer 1

Distance travelled divided by time taken

Question 2

What does a horizontal straight line on a distance time graph represent

Answer 2

A stationary object

Question 3

What does a straight slope on a distance time graph represent

Answer 3

An object moving at a constant speed

Question 4

What is instantaneous speed

Answer 4

The speed of an object over a very short period of time

Question 5

How can you find instantaneous speed from a distance time graph

Answer 5

Draw a tangent to the graph at the given time and calculate its gradient

Question 6

Should the gradient triangle be large or small

Answer 6

As large as possible to reduce percentage uncertainty

Question 7

What are the features of a scalar quantity

Answer 7

It has only a magnitude with no direction

Question 8

What are the features of a vector quantity

Answer 8

It has magnitude and direction

Question 9

Is displacement a vector or scalar quantity

Answer 9

Vector

Question 10

Is speed a vector or scalar quantity

Answer 10

Scalar

Question 11

What is the formula for average velocity

Answer 11

Change in displacement divided by time taken

Question 12

What is the formula for acceleration

Answer 12

Change in velocity divided by change in time

Question 13

Is acceleration a vector or scalar quantity

Answer 13

Vector because its determined from velocity which is also a vector

Question 14

How can the acceleration of an object be found from a velocity time graph

Answer 14

By calculating the gradient

Question 15

What does a curve on a velocity time graph suggest

Answer 15

A changing acceleration

Question 16

How can displacement be found from a velocity time graph

Answer 16

By calculating the area under the graph

Question 17

What are the equations of motion known as

Answer 17

The SUVAT equations

Question 18

What does each letter of SUVAT stand for

Answer 18

Displacement, initial velocity, final velocity, acceleration and time

Question 19

What is stopping distance

Answer 19

Total distance travelled between the moment a reason to stop is identified and the vehicle becoming stationary

Question 20

What are the two components of stopping distance

Answer 20

Thinking distance and braking distance

Question 21

List the main factors that affect stopping distance

Answer 21

Speed, condition of brakes, tyres, roads, weather and alertness

Question 22

What is the formula for thinking distance

Answer 22

Speed multiplied by the reaction time

Question 23

What does it mean to be in freefall

Answer 23

When an object is accelerating under gravity with no other forces acting on it

Question 24

Describe the basic idea for determining G

Answer 24

Drop a heavy ball over a known distance and time its descent, the issue with this is that it all occurs very quickly

Question 25

Describe the electromagnet and trapdoor method for determining G

Answer 25

An electromagnet holds a steel ball above a trapdoor, when the current switches off a timer is triggered and the magnet releases the steel ball, when hitting the trapdoor the timer is stopped

Question 26

What causes inaccuracy in the electromagnet and trapdoor method for determining G

Answer 26

Air resistance and the slight delay of timers, this can be improved by using a heavier ball and a much longer drop

Question 27

Describe the light gate method for determining G

Answer 27

Two light beams are set up one above the other, with detectors connected to a timer. When the ball falls through the first beam the timer is started and when it hits the second the timer is stopped, the distance is known.

Question 28

Describe the taking pictures method for determining G

Answer 28

A small metal ball is dropped from rest next to a meter rule, the fall is recorded on video or a rapid fire camera is used to capture the event, alternatively a stroboscope illuminates the scene with rapid flashes, the video can be examined to calculate G

Question 29

How can G be determined from plotting a graph

Answer 29

A distance against time squared graph will have half the value of G

Question 30

How are vertical and horizontal components of velocity treated

Answer 30

independently of each other

Question 31

Why does horizontal velocity remain constant

Answer 31

The result would be g cos 90 which results in zero

Question 32

How is actual velocity found given horizontal and vertical

Answer 32

v = sqrt(horizontal v^2 + vertical v^2)

Question 33

How is the angle to the horizontal found

Answer 33

Inverse tan of vertical velocity divided by horizontal velocity

Question 34

Write a statement for horizontal velocity

Answer 34

v cos theta

Question 35

Write a statement for vertical velocity

Answer 35

v sin theta