A man works on a striaght road from his home to market 2.5km away dwith a speed of 5km/h. Finding the market closed, he instantly truns and walk back home with a speed of 7.5km/h. The average speed of the man over the interval of time 0.40min. Is equal to?

5.625km/h

Explanation:

We are given that

Distance between home and market, d=2.5 km

Speed, v1=5km/h

Speed, v2=7.5 km/h

We have to find the average speed of the man over the interval of time 0 to 40min.

Time,

Using the formula

1 hour =60 min

Distance traveled by man in 10 min with speed 7.5 km/h=

Therefore,

Total distance covered=2.5+2.5/2=3.75 km

Time=40 min=40/60=2/3 hour

Average speed=

Average speed=

the independent variable, the one that is intentionally manipulated, is whether or not the car hits the barrier.

the dependent variable, the one that you measure the response in, is the distance that the washers travel.