When an element has a low specific heat, this means that it requires less energy to increase the temperature of this element. Specific heat is measure in Joules/GramDegreeCelcius because it measures the amount of joules required to raise one gram of the element by one degree Celcius.
It'll last 20 hours. If it travels 110 miles in one hours, 110 times 20 equals 2,200.
<h2>Right answer: acceleration due to gravity is always the same </h2><h2 />
According to the experiments done and currently verified, in vacuum (this means there is not air or any fluid), all objects in free fall experience the same acceleration, which is <u>the acceleration of gravity</u>.
Now, in this case we are on Earth, so the gravity value is
Note the objects experience the acceleration of gravity regardless of their mass.
Nevertheless, on Earth we have air, hence <u>air resistance</u>, so the afirmation <em>"Free fall is a situation in which the only force acting upon an object is gravity" </em>is not completely true on Earth, unless the following condition is fulfiled:
If the air resistance is <u>too small</u> that we can approximate it to <u>zero</u> in the calculations, then in free fall the objects will accelerate downwards at and hit the ground at approximately the same time.
In order to answer either of these, we need to know the energy content of coal ... like kwh (or joules or BTU) in each kilogram (or pound or ton) of coal.