Scenario A: 120 J of work is done in 6 s. Scenario B: 160 J of work is done in 8 s. Scenario C: 200 J of work is done in 10 s. W
2 answers:
You might be interested in
Answer:
<em>765,000 Joule</em>
Explanation:
<u>Principle of Conservation of Energy </u>
The total energy in an isolated system cannot be created or destroyed, but transformed. Moving objects have kinetic energy, objects placed in some height above a reference level have gravitational potential energy. When they change their motion variables, one energy converts into the other, but if the numbers don't fit, we know there was some other type of energy acting into the system. The most common reason for energy 'losses' is the thermal energy, produced when objects move in rough surfaces or take friction from the air.
The 7,500 kg truck is originally traveling at 20 m/s to a certain height we'll set to 0. Thus, its total energy is
When it comes to a stop, its speed is 0 and its height is 10 m higher than before. It means all the kinetic energy was transformed into other types of energy. The gravitational potential energy is
Since this number is not equal to the previous value of the energy, the difference is due to thermal energy dissipated by friction
To solve this problem it is necessary to apply Boyle's law in which it is specified that
Where,
and
are the initial pressure and volume values
and
are the final pressure volume values
The final pressure here is the atmosphere, then
Pressure at the water is given by,
Using Boyle equation we have,
Therefore the volume of the lungs at the surface is 5.9L