The average speed of Joshua during that time is 2500 m/h.
Explanation:
It is given that Joshua started cycling at 5:15 pm. By 8:09 pm he has covered a distance of 7250 m.
The total time taken by Joshua from 5:15 pm to 8:09 pm is
Dividing we get,
Adding, we have,
Thus, the total time taken by Joshua is
To determine the average speed we use the formula,
where and
Hence, substituting the values we have,
Dividing, we get,
Thus, the average speed of Joshua during that time is 2500 m/h.
The increasing and decreasing intervals are marked on the graph and attached below.
The red arrow mark shows the part where graph is decreasing
The green arrow mark shows the part where graph is increasing
There is no end point or starting point for the graph
The graph starts decreasing at -∞ and it decreases till it reaches -2.5
Also the graph start decreasing at 0 and goes to +∞
So we have two decreasing intervals
(-∞ , -2.5) U (0, ∞)
The graph starts increasing at -2.5 and it increases till it reaches 0
So increasing interval is
(-2.5, 0)
