P4 - Speed

Question 1

Why are averages for speed used?

Answer 1

This is because cars can never maintain a constant speed, as they accelerate when starting up and the speed is affected by traffic. This means an average is used.

Question 2

What is the formula for speed?

Answer 2

Speed = distance / time

Question 3

How can instantaneous speed be found?

Answer 3

White lines are used to show the distance covered by a car in set time by a speed camera, allowing speed to be calculated.

Question 4

Describe displacement…

Answer 4

This is the distance with a direction from its given point at a given time. This can be shown on a displacement graph and is positive or negative.

Question 5

Describe velocity…

Answer 5

This is the speed in a set direction, such as 20 km/h due North. This is negative when a car turns around and travels in an opposite direction.

Question 6

What is instantaneous velocity?

Answer 6

This is the speed in a set direction at a given time.