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.?

ADE.me

4 years ago

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...

VPETERS2002

4 years ago

At the start the ball has potential energy = 8kg * 9.81 m/s² * 100 m

Potential energy = 7,848 J

In falling the ball maintains this energy until it hits the ground. In falling the PE is converted to kinetic energy - but the total energy doers not change.

After falling 40 m ,

PE = 8 kg * 9.81 m/s² * 60 m = 4709 J

and the KE = 7848 J - 4709 J = 3139 L

total energy = 7848 J