W=(A)(P)(delta X)
W= (7.40x10^-3)(9.5x10^5)(7.20x10^-2)
W= -506.16J
Please see if I am doing this problem right.
A mixture of gasoline vapor and air is placed in an engine cylinder. The piston has an area of 7.4 X 10^-3 m^2 and is displaced inward by 7.2 X 10^-2 M. If 9.5 X 10^5 Pa of pressure is placed on the piston, how much work is done during this process? Is work being done on or by the gas mixture?
Given: A= 7.4 X 10^-3 m^2 d= 7.2 X 10^-2 m
P= 9.5 X 10^5 PA= 9.5 X 10^5 N/m^2
^^^ is that right???
Unknown: V= ?, W=?
V= Ad
W= PV
V= (7.4 X 10^-3 m^2) (7.2 X 10^-2 m) = 5.3 x 10^-4 m^3
W= (9.5 X 10^5 N/m^2) (5.4 X 10^-4 m^3)= 513 J.
W done by the gas= 513 J.
Is any of this right at all or am I completely doing this wrong?
also, how do i figure out if work is being done on or by the gas mixture?
3 answers
-506.2 J
Yes, that is correct. The negative sign indicates that work is being done on the gas mixture by the piston.
0 answers