Water is falling from height of 84 m. If half of the energy of water is converted into heat, the increase in the temperature of the water at the bottom is:

what are the options??? to choose the answer from?

Explanation:

so its 0.098*C

Explanation:

Let m gram be the mass of water.

Then potential energy of water is:

P.E.=mgh

=m×980×8400

Since potential energy is converted to kinetic energy

P.E.=K.E.

K.E.=m×980×8400

Half of kinetic energy is converted into heat.

Then  heat energy:

Heat energy=

2

1

×m×980×8400

Convert joule into calories

heat=

4.2×10

7

m×980×4200

=m×0.098

But heat is:

Heat=msΔT

∴msΔT=m×0.098

m×1×ΔT=m×0.098

ΔT=0.098C

Rise in temperature of water is =0.098

∘

C .

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.