physics
posted by Jade .
Tarzan, mass 85 kg, swings down on the end of a 28 m vine from a tree limb 4.4 m above the ground. How fast is Tarzan moving when he reaches the ground?

Use energy conservation.
M g H = (1/2) M V^2
V = sqrt (2gH)
H is the vertical distance that he falls, 4.4 m.
g = 9.8 m/s^2
His mass will not matter. It cancels out. 
a car increases its speed from 50km/hr to 75km/hr in 15mintues. what is the acceleration of the car