True or false : boyle’s law states that, as the pressure of a gas increases, the volume decreases.

True, but only if the temperature of the gas doesn't change ...
which is pretty hard to manage when you're compressing it.

I think Boyle's law actually says something like

       (pressure) x (volume) / (temperature)  =  constant.

So you can see that if you want to say anything about two of the
quantities, you always have to stipulate that the statement is true
as long as the third one doesn't change.

4. 50x10= 500m/s 5. 52m/s