Question

only for a expert :
a body of mass 1.5 kg is thrown vertically upwards with an initial velocity of 15m/s. what will be its potential energy at the end of 2 second?( take g=10m/s^2)

Answer 1

h = ut+1/2at²

h= 30 - 0.5(10)4 = 10

P = mgh = 1.5 (10)(10)

= 150J

Answer 2

m = 1.5 kg
u = 15 m/s
mgh =PE = ?
t = 2
a = -g = - 10 m/s^2

h = s = ut + 1/2 at^2
h = 15×2 + 1/2 (-10) 2×2
h = 30 - 20
h = 10 m


mgh = 1.5 × 10 × 10
PE = 150 Joule!!!