Question

a body of mass 2 kg is thrown vertically upward with an initial velocity of 20 metre per second what will be its potential energy at the end of 2 seconds​

Answer 1

Answer:

h=vt+1/2at^2

h=20×2 + 1/2 × (-10)2×2

h= 40 + -(20)

h=20 m

potential energy

U=mgh

U=2 × 10 × 20

U=400J

Answer 2

Explanation:

h

$h = ut + \frac{1}{2} a {t}^{2}$

so, h= 20×2-1/2×9.8×2×2. (because a= -g)

h=20.4m

PE=mgh

m=2kg

g= 9.8

h=20.4

PE=2×9.8×20.4

=399.84J