Michael drove to a friends house at a rate of 40 mph. he returned the same route at a rate of 45 mph. the driving time for the round trip was 4 hours. what was the distance michael traveled?

151.58 miles

Explanation:

given,

total trip time = 4 hr                      

speed when drove to a friends house = 40 mph

speed when drove back = 45 mph          

40 x + 45 x = 4 × (45 × 40)                      

95 x = 7200                                      

x = 75.79 miles                                    

Total distance travel by michael  is 2 x = 2 × 75.79 = 151.58 miles

c)as speed changes, wavelength and frequency change.

everything changes!