Question

Devin went for a bicycle ride . the graph below shows his trip. Note : distance distance is the number of kilometers from home

Answer 1

Given the graph in the attached image;

a.

We want to find the speed during the first four AB and the second hour BC.

Let us write out the coordinates of A,B and C on the graph;

`\begin{gathered} A=(0,0) \\ B=(1,10) \\ C=(2,15) \end{gathered}`

The speed for each hour is the slope of the line within that time.

So, the slope of line AB is;

`\begin{gathered} m_(AB)=(\Delta y)/(\Delta x)=(10-0)/(1-0) \\ m_(AB)=10\text{ km/h} \end{gathered}`

the slope of line BC is;

`\begin{gathered} m_(BC)=(15-10)/(2-1)=(5)/(1) \\ m_(BC)=5\text{ km/h} \end{gathered}`

Therefore, the speed at the first hour AB is;

`10\text{ km/h}`

The speed at the second hour BC is;

`5\text{ km/h}`

b.

Comparing the speed in the first hour AB to the speed in the second hour BC as calculated in question a above.

We can see that the speed in the first hour is more than the speed in the second hour.

The speed between A and B is double the speed between B and C.

Since the speed between A and B is 10 km/h and the speed between B and C is 5 km/h, so the speed between A and B is double the speed between B and C.