Respuesta :
given GPE=M*g*h
KE= 0.5*Mass *velocity squared
something falls n before it hits the ground,
by conservation of energy
GPE loss = KE gain
e.g. A 0.05 kg-coin is dropped from the top of a skyscraper that is 100 meters high.
so M=0.05, g=9.8m/s^2, h=100m
GPE loss=M*g*h=0.05*9.8*100
=49J
KE gain=0.5*Mass *velocity squared=GPE loss
0.5*0.05*velocity squared=49
velocity squared=49/0.5/0.05=1960
velocity=sqrt(1960)=44.27m/s
I will solve it using a different set of equations from kinematics. The same principles are the same but the equations look different. Specifically
final velocity^2 = initial velocity^2 + 2(acceleration)(displacement)
In this example, the coin has no initial velocity, acceleration is by gravity and the displacement is 100m
final velocity^2 = 0 + 2(9.8)(100)=1960
final velocity = (1960)^(1/2) = 44.3m/s