Question

An
object of 4 kg is raised from a height
of 20cm to 80cm . find change in its
potential energy​

Answer 1

Answer: 2400 J

Explanation:

P.E = mgh

Change in P.E = Final P.E - Initial P.E

Initial P.E = mgh=4*10*20-----(g=10m/s)

=800 J

Final P.E = mgh = 4*10*80=3200J

Change in P.E = 3200-800=2400 Joules

Mark as Brainliest.

Answer 2

Answer:

1000 J

Explanation:

Given :

Mass of the object M=40kg

Height upto which it is raised h=5 m

Potential energy P.E=Mgh

P.E=40×10×5=2000J

Let its kinetic energy be E

k

when it is half way down i.e h

′

=

2

h

According to conservation of energy,

K.E

i

+P.E

i

=K.E

f

+P.E

f

0+2000=E

k

+Mg

2

h

∴ 2000=E

k

+40×10×

2

5

⟹E

k

=1000J