Question

An object of mass m is falling through a height h. At what height from the top its potential energy becomes 30% of the kinetic energy
​

Answer 1

Answer:

Solutions:

mass of the object = m

let the total height be = 100 meters

let the height that is covered be = x

so distance needed to cover = (100-x) meters

so let the velocity be = v

so,

kinetic energy = mv^2×1/2

k.e = (mv^2)/2

as mentioned in above

30% of the kinetic energy

so,

(mv^2)/2 ×30÷100 = m×g×h

(mv^2)/2 ×30÷100 = m× 9.8 × 100-x

so,

x= 980m -3(mv^2)÷20

x= {19600m -3(mv^2)}/20 meters