Question

a object of mass 1kj is allowed to fall from a height of 50 m calculate the kinetic and potential energy at end of 2 seconds take g=10m/s²​

Answer 1

Answer:

given that,

mass m = 1kg

height h = 50m

time t = 2sec

gravity g = 10m/sec²

kinetic energy K = ?

potential energy P = ?

Explanation:

for free falling initial velocity u = 0

now procced,

from 1st equation of NLM

v = u+at

v = 0+10×2

v = 20m/sec

&from 3rd equation of NLM,

v² = u²+2as

20² = 0+ 2×10×s

400 = 20s

s = 20m

so,

K = (1/2)mv²

= (1/2)×1×20²

= 200joule answer

P = -mgh

= -1×10×20

= -200joule answer

-ve sign indicated that potential decrease