# Thread: Mechanical principles engineering question help??

1. ## Mechanical principles engineering question help??

A 4 stroke car diesel engine cylinder has a diameter (bore) of 90mm and the length of the piston stroke is 85mm. When the piston is at bottom dead centre after the intake stroke, the induced air in the cylinder is at 100 KPA and temperature 30c At top dead centre at the end of the compression stroke, the piston has compressed the air into a clearance volume of 30cm3, at which point the pressure is 4.8MPA. Assuming at which the properties of a perfect gas calculate;

a) The temperature of the compressed air in the cylinder
b) The mass of the air in the cylinder

The characteristic gas for air is 287 j/kgK

I know that for a you have to use p1v1/t1 = p2v2/t2 but am not sure how to work it out
and for b i know that you have to use p1vi = mvu but again i am not sure how to calculate it.

I would really appreciate any help, thanks so much for helping!!

Aaron

2. We appreciate your willingness to openly admit that this is a homework problem. Most try to hide that fact.

Check our policies. You won't find an answer here. The value of homework is in its pain. No pain, no knowledge, no gain.

3. Oh right didn't realize that, thanks anyway!! I will get the answer eventually

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