6.5.4.1 Describing Motion along a line

Question 1

What does a scalar quantity mean?

Answer 1

A quantity which has magnitude (size) only

Question 2

What does a vector quantity mean?

Answer 2

A quantity which has magnitude (size) and direction

Question 3

Is distance a scalar or vector quantity?

Answer 3

Scalar (it has magnitude only)

Question 4

Is displacement a scalar or vector quantity?

Answer 4

Vector (it has size and direction)

Question 5

What are the similarities and differences between distance and displacement?

Answer 5

Both measured in metres (m)

Distance - scalar, displacement - vector

Question 6

A object travels three metres. Is this a measurement of distance or displacement?

Answer 6

Distance - it has magnitude (size) only.

Question 7

A object travels three metres north. Is this a measurement of distance or displacement?

Answer 7

Displacement - it has a magnitude and direction.

Question 8

Is speed a scalar or vector quantity?

Answer 8

Scalar (it has magnitude only)

Question 9

What factors can affect the walking/cycling speed of a person?

Answer 9

Age
Terrain
Fitness
Distance already traveled (tiredness)

Question 10

What is the difference between average speed and instantaneous speed?

Answer 10

Average speed is a measure of the speed of an object over the whole journey; instantaneous speed is the speed at that particular point in the journey.

Question 11

What are the typical speeds for walking, running and cycling?

Answer 11

walking ~ 1.5 m/s
running ~ 3.0 m/s
cycling ~ 6.0 m/s

Question 12

What is the typical value for the speed of sound?

Answer 12

~ 330 m/s

Question 13

What is the equation for speed?

Answer 13

Speed (m/s) = distance traveled (m) / time taken (s)

Question 14

What equipment would be required to measure the speed of a person running?

Answer 14

Distance - Tape measure or trundle wheel

Time - stopwatch or timer

Question 15

Is velocity a scalar or vector quantity?

Answer 15

Vector (it has size and direction)

Question 16

What are the similarities and differences between speed and velocity?

Answer 16

Both measured in m/s, both are a rate of change (something divided by time)
Speed - scalar, velocity - vector
speed = distance/time, velocity = displacement/time

Question 17

(HT only) How do speed and velocity vary for an object moving in a circle?

Answer 17

speed is constant
velocity varies from positive to negative and back to positive. Total displacement in one loop is zero (its back where it started) so velocity is zero.

Question 18

On which axis do distance and time go on a distance-time graph?

Answer 18

Time - x-axis

Distance - y-axis

Question 19

What type of motion does a flat line represent on a distance time graph?

Answer 19

A object which is stationary/at rest/still

Question 20

What type of motion does a straight sloped line represent on a distance-time graph?

Answer 20

An object traveling at a constant speed

Question 21

How can you determine the speed of an object from a distance-time graph?

Answer 21

Its the gradient (rise/run)

Question 22

How would accelerating motion be represented on a distance-time graph?

Answer 22

A curved line

Question 23

How can you tell if the speed of an object is faster or slower than another?

Answer 23

The gradient of the line representing the faster motion is higher/steeper than the slower motion (lower/shallower gradient)

Question 24

(HT only) How can the instantaneous speed of an object be found on a curved (accelerating) distance time graph?

Answer 24

Draw a tangent to the line at the time required. Determine the gradient of the tangent.

Question 25

What is the equation for acceleration?

Answer 25

acceleration (m/s2) = change in velocity/time taken

Question 26

What is the unit of acceleration?

Answer 26

m/s2

Question 27

Determine whether the following quantities are vectors and scalars? Distance, displacement, speed, velocity, acceleration.

Answer 27

Scalar - distance, speed

Vector - displacement. velocity, acceleration

Question 28

On which axis do velocity and time go on a velocity-time graph?

Answer 28

Time - x-axis

Velocity - y-axis

Question 29

How could you represent an object at rest on a velocity-time graph?

Answer 29

A flat line along the x-axis (y = 0)

Question 30

How could you represent an object traveling at a constant velocity on a velocity-time graph?

Answer 30

A flat line. (Along the x-axis is a constant velocity of 0 m/s, but not a safe answer)

Question 31

What type of motion does a straight sloped line represent on a velocity-time graph?

Answer 31

An object which is accelerating

Question 32

How can the acceleration be determined from a velocity-time graph?

Answer 32

The gradient (rise/run)

Question 33

(HT only) What does the area under a velocity-time graph represent?

Answer 33

The displacement

Question 34

(HT only) How is the displacement of an accelerating object determined?

Answer 34

The area of the triangle (1/2 x base x height).

Question 35

What do the terms ‘v’, ‘u’, ‘a’ and ‘s’ mean?

Answer 35

v - final velocity
u - initial velocity
a - acceleration
s - displacement

Question 36

What is the acceleration due to gravity near the surface of the Earth?

Answer 36

9.8 m/s2

Question 37

Describe what happens when an object is dropped near the surface of the Earth.

Answer 37

Initially accelerates at 9.8 m/s2
Air resistance increases as speed increases
Until air resistance equals the weight
There is no resultant force and the object travels at terminal velocity

Question 38

What is the name of the maximum velocity traveled by an object falling due to gravity?

Answer 38

Terminal velocity.

Question 39

Describe an investigation to determine the speed of water ripples in the laboratory.

Answer 39

Set up an oscillator to create ripples; set up a strobe light that creates a still pattern in the waves; determine the frequency from the signal generator/strobe light; using f = 1/T; measure the wavelength with a ruler; use wave speed = frequency x wavelength.