Given data
*The given mass of the cyclist is m = 73 kg
*The given mass of the bicycle is M = 8 kg
*The bicycle travels halfway down at a height is h = 20 m
*The hulk is traveling at a speed is v = 10 m/s
The expression for the total mechanical energy is given as
*Here g is the acceleration due to the gravity
Substitute the known values in the above expression as
Hence, the total mechanical energy is U_m = 19926 J