1) A tourist from England travels 100 miles from Laramie to Pine Bluffs, then returns to Laramie via Ft Collins traveling 145 miles on the return route. The trip took 4 hours to complete. Calculate the average speed of tourist's car in miles per hour.
2) You push on a 5 Kg mass that is resting on a horizontal surface with a force of 50 N. The horizontal friction force is 20 N. Calculate the acceleration of the 5 Kg mass.
3) A car traveling at 25 m/s ( about 55 mph) crashes into a road barrier and comes to a stop in 0.2 sec. What is the average force in Newtons felt by a 75 Kg person in a set belt?