physics
posted by valentino anthony on .
a ball of mass 8kg falls from rest from a height of 100m.neglecting air resistance,calculate its total energy after falling a distance of 40m

Assuming that potential energy is defined so that the value at ground level is zero, the total kinetic energy starts at M*g*H and remains that value until it hits the ground. Potential eneergy is changed to kinetic as it falls.
M = 8 kg
g = 9.8 m/s^2
H = 100 m
Total energy = ____ J
(Just multiply the three numbers) 
7840

Datas.mass=8kg,height=100m,distance=40m.And the question state find the total energy,so the addtion of kinectic & potential energy is the total energy. Ep=m*g*h.while g is constant at 10m/s^2.Ek =1/2 m*v^2.distance wil be represent velocity, so v=4om.after that add both answer 2gether.the answer is our total energy

E.p is equal to mgh
8 mutiply by 10 multiply by 100 is equal to 800joules 
This question is just straight forward. We know that it all about EK and EP but it common sense to answer this question. It says
8kg falls from rest and
the height is 100 m
Neglect air resistance and calculate the total energy after falling a distance of 40 m.
Fall from rest _ 8*100= 800.
Total energy after falling is 40 *100=4000.
Then you add the both answers together, that is falling from rest * total energy after falling, which is; 800 + 4000 = 4800joules... 
Its k.E= 0.5*m*v^2 while v^2 =2gh/2gh. Therefore k.E = 0.5*8* 44.7^2 =

89.50 or129.4

4,800j