Gravitational potential energy is energy.
The unit of energy is the Joule.
1 Joule = 1 kilogram-meter² / sec²
Answer:
1.34352 kg
Explanation:
= Mass of water falling = 1 kg
h = Height of fall = 0.1 km
= Change in temperature = 0.1
c = Specific heat of water = 4186 J/kg K
g = Acceleration due to gravity = 9.81 m/s²
= Mass of water in the vessel
Here the potential energy will balance the internal energy

Mass of the water in the vessel is 1.34352 kg
Answer:
17.64 km/h
Explanation:
mass of car, m = 1000 kg
Kinetic energy of car, K = 1.2 x 10^4 J
Let the speed of car is v.
Use the formula for kinetic energy.

By substituting the values

v = 4.9 m/s
Now convert metre per second into km / h
We know that
1 km = 1000 m
1 h = 3600 second
So, 
v = 17.64 km/h
Thus, the reading of speedometer is 17.64 km/h.
Answer:
mass = 4kg
Explanation:
Kinetic Energy = 1/2 x m x v²
where m = mass and v = velocity
So,
KE = 50
1/2 × m × 5² = 50
1/2 × m × 25 = 50
m = (50 x 2)/25
m = 100/25
m = 4 kg