Given :
The mass of the balloon was 1890 kg and had a volume of 11,430 m3 .
The balloon floats at a constant height of 6.25m above the ground.
To Find :
The density of the hot air in the balloon.
Solution :
We know,
Volume × ( Density of surrounding air - Density of hot air ) = mass
Putting given values in above equation, we get :
Therefore, the density of hot air in the balloon is 1.125 kg m³.
To solve this problem it is necessary to apply to the concepts related to energy conservation. For this purpose we will consider potential energy and kinetic energy as the energies linked to the body. The final kinetic energy is null since everything is converted into potential energy, therefore
Potential Energy can be defined as,
Kinetic Energy can be defined as,
Now for Conservation of Energy,
Therefore the highets position the car reaches above the bottom of the hill is 40.02m