Answer:
The effect of gravity on object makes objects stable and not floating in the air . It also makes any object thrown up to return back
An example of using muscular strength would be doing things like lifting weights and things like that.
We can use the equation of state for an ideal gas to answer the question:

or, by rewriting it,

where p is the gas pressure, V its volume, T its temperature, n the number of moles of the gas and R the gas constant.
When the gas is sprayed from the can into the room, its volume V has increased, while n (the number of moles of the gas) stayed the same. Since R is a constant and the temperature T also stayed constant, if we look at the formula we see that the numerator didn't change, while the denominator (V) has increased, so the pressure of the gas has decreased.