Answer: to only change one factor in an experiment or test
Answer: the answer is most likely that the mirror is 120 cm tall as well
Explanation:mark brainliest PLEASE.
Answer:
B. 
Explanation:
Assuming we are dealing with a perfect gas, we should use the perfect gas equation:

With T the temperature, V the volume, P the pressure, R the perfect gas constant and n the number of mol, we are going to use the subscripts i for the initial state when the gas has 20 cubic inches of volume and absolute pressure of 5 psi, and final state when the gas reaches 10 psi, so we have two equations:
(1)
(2)
Assuming the temperature and the number of moles remain constant (number of moles remain constant if we don't have a leak of gas) we should equate equations (1) and (2) because
,
and R is an universal constant:
, solving for 


Zero.
Acceleration is defined as the change in velocity over time.
Since in your case there is no change, there is no acceleration, so it is zero:
Or in formula: <span>a=<span><span>Δv</span>t</span></span>
Where a=acceleration, <span>Δv</span>=change in velocity and t=time