Gasoline containing a total of 44,000 kJ of energy was burned in a car
engine. The table below shows some information related to the energy
output of the car from burning the gasoline. How much potential energy
from the gasoline was converted to mechanical energy? Energy Output
in (kJ) Thermal = 36,080 Electrical = 1,760 Mechanical = ?? *
6,160 kJ
14,960 kJ
0
20,240 kJ
44,000 kJ

6,160 kJ

Explanation:

We can solve this problem by using the law of conservation of energy.

In fact, the sum of the different types of energy in output must be equal to the total energy in input. So we can write:

where:

is the chemical energy contained in the gasoline (the energy in input)

is the thermal energy in output

is the electrical energy in output

is the mechanical energy in output

In this problem:

So the mechanical energy is:

it can be observed without changing the identity of the object.

it depends on what substance you're talking about as well as many other factors. in quantum mechanics, the observation of particles affects the observers ability to measure certain properties. for example: you can know the velocity of a particle, but you can't know it's position; or you can know it's position, but not it's velocity. it's like trying to find out where a grain of sand is by throwing other grains of sand at it. once you find out where it is, it's been moved. it's also like trying to find an answer to the question of whether or not a tree falling in a forest makes a sound if nobody is there to hear it. paradoxically, the only way to find out is to be there and hear it.