Question

If a object is falling form a height 200 m then find kinetie and potential energy after 5 sec with mass 2 kg

Answer 1

Here, h= 200m, m= 2kg, u= 0 and t= 5s

now, Velocity of the object after 5s of falling,
v = u + gt= 0 + 9.8*5=49.0m/s
Therefore,

Kinetic Energy at 5s = 1/2 * mv^2
K. E. = 0.5* 2 * 49*49= 2401 joule

Now, the distance covered by the object during its 5s motion,

h1 = ut + 1/2 *gt^2= 0 + 0.5*9.8*25=122.5

now,
new height of object = h-h1= 200-122.5=77.5m
Now,
P. E. = mg(h-h1)= 2 * 9.8 * 77.5= 1519 joules