On September 15, 1896 in near Waco, Texas, William George Crush parked two locomotives at opposite ends of a 6.4-km-long track, fired them up, tied their throttles open, and then allowed them to crash head-on at full speed (as seen above) in front of 40,000 spectators (more people than lived in the state’s second-largest city at the time). Hundreds of people were hurt by flying debris; several were killed. Assuming each locomotive weighed 1.2×106N and its acceleration was a constant 0.26 m/s2, what was the total kinetic energy of the two locomotives just before the collision?

A parachutist drops freely from an aeroplane for 10 s before the parachute opens out. Then he descends with a net retardation of 2.5 m/s2, If he bails out of the plane at a height of 2495 m and g= 10 m/s², his velocity on reaching the ground will be (a) 5 m/s 87. (b) 10 m/s (c) 15 m/s" (d) 20 m/s

In World War II, there were several reported cases of airmen who jumped from their flaming airplanes with no parachute to escape certain death. Some fell about 20,000 feet (6000 m), and some of them survived, with few life- threatening injuries. For these lucky pilots, the tree branches and snow drifts on the ground allowed their deceleration to be relatively small. If we assume that a pilot's speed upon impact was 123 mph (54 m/s), then what was his deceleration?  Assume that the trees and snow stopped him over a distance of 3.0 m.