Question

an object of mass 12 kg is at a certain height above the ground. What is it's P.E. ? if the object is allowed to fall find K.E. just before touching the ground and also it K.E. when it is half way down

Answer 1

MASS (M) = 40 KG

HEIGHT (H)=   5 M

WE KNOW, POTENTIAL ENERGY (U) = MGH   G = ACCELERATION DUE TO GRAVITY = 9.8 M S−2

OR U = 40 X 9.8 X 5 = 1960 J

(B)

NOW ,

IF THE OBJECT IS AT HALF-WAY DOWN,

THE POTENTIAL ENERGY OF THE OBJECT  = KINETIC ENERGY/2

                                                              =1960 / 2 = 980 J.