1.1 Distance, displacement, speed and velocity

Question 1

What is a scalar?

Answer 1

A physical quantity that has magnitude but no direction.

(ie. speed)

Question 2

What is a vector?

Answer 2

A physical quantity that has a magnitude and a direction

(ie. velocity)

Question 3

Give four examples of vector quantities:

Answer 3

• Displacement (distance in a given direction)
• acceleration
• weight
• momentum

Question 4

Give four examples of scalar quantities:

Answer 4

• Speed
• Distance
• Time
• Mass
• Energy

Question 5

A person walks 5m North and 5m South. What is their distance travelled and their displacement?

Answer 5

10m travelled and a displacement of 0m

Question 6

Describe the velocity of an object traveling at a constant speed in a circle?

Answer 6

The velocity is constantly changing, because the direction is changing.

Question 7

In m/s, approx. how quickly does a person walk, run and cycle?

Answer 7

• walking – 1.5
• running – 3
• cycling – 6

Question 8

In m/s, approx. how quickly does a car travel (built up area and motorway), a train travel and a plane travel?

Answer 8

• Car (built up area ) – 13
• Car (motorway) – 30
• Train – 55
• Plane – 250

Question 9

In m/s, approx. what is the speed of sound in air, and what is the range of wind speed?

Answer 9

• sound – 340
• wind – 5 to 20

Question 10

What is the formula for speed (in terms of distance and time)?

Answer 10

speed = distance / time

Question 11

How can an object have a constant speed and a changing velocity?

Answer 11

If it’s travelling in a circle (or not in a straight line).

Question 12

Give the units for speed, distance and time:

Answer 12

• speed – m/s
• distance – m
• time – s