Question

Calculate his speed during the first hour (AB) and the second hour (BC) How does the speed between A and B compare with the speed between B and C explain what segment CD tells you about Devin's motion which segment of the graph shows that Devin was changing speeds what information can you determine from segment EF

Answer 1

To find the speed, here we find the slope or use the speed formula below:

`\text{Speed = }(dis\tan ce)/(time)`

Or we can use the slope formula:

`m=(y2-y1)/(x2-x1)`

a) Speed during the first hour:

Let's use the slope formula

Given the points:

(x1, y1) ==> (0, 0)

(x2, y2) ==> (1, 10)

`AB=(10-0)/(1-0)=(10)/(1)=10`

Speed during the first hour = 10 km/h

Speed during the second hour:

Given the points BC:

(x1, y1) ==> (1, 10)

(x2, y2) ==> (2, 15)

`BC=(15-10)/(2-1)=(5)/(1)=5`

Speed during the second hour BC = 5 km/h

b) To compare the speed between AB and BC:

`AB-BC=10-5=5\text{ km/h}`

The speed between A and B is greater than the speed between B and C by 5 km/h.

c) From the graph, segment CD indicates that Devin made a constant movement during segment CD. His distance from home does not increase or decrease.

This is because CD is a horizontal line. A horizontal line indicates there's a constant movement on the graph.

d) Section DE shows that Devin was changing speed.

This is because the direction of the graph started going downwards from DE.

e) Section EF indicates that Devin was close to his home because the graph started going downwards and his speed was decreasing.