Answer: 81.85 km/hr
Converting m/sec into km/hr, 25 m/sec = 90 km/hr
Average =
Time = 50/90 = 5/9 hr
next 120 km at an average speed of 80km/h
=> Time = 120/80 = 3/2 hr
last part of its journey at an average speed of 90km/h in 35 Minutes
time = 35 minutes = 35/60 hr = 7/12 hr
Distance covered = 90 * 7 /12 = 105/2 km
Total Distance = 50 + 120 + 105/2 = 435/2 km
Total time = 5/9 + 3/2 + 7/12 = ( 20 + 54 + 21) /36 = 95/36
Average speed = (435/2)/(95 /36) = 432 * 18 /95 = 81.85 km/hr
Ouch! That is hard but I can do it. First, find the area of the triangle. (for both is 60) Then find the area of the rectangle (base) which is 48. Then do the rectangles on the sides which are 72 each (for both is 144) Then add it all together and get 252 ft squared or cubed.
Real number, rational number
