When air expands adiabatically (without gaining or losing heat), its pressure P P and volume V V are related by the equation P V 1.4 = C PV1.4=C, where C C is a constant. Suppose that at a certain instant the volume is 450 cm 3 450 cm3 and the pressure is 80 kPa 80 kPa and is decreasing at a rate of 10 kPa/min 10 kPa/min. At what rate is the volume increasing at this instant? (Round your answer to the nearest whole number.)

Rate at which the volume is increasing,

Explanation:

Volume, V = 450 cm³

Pressure, P = 80 kPa

Rate of decrease in pressure,

Rate of increase in volume,

The equation relating the pressure, P and the volume,V

..............(1)

Differentiating both sides with respect to t (Using Products rule)

..............(2)

Substitute the necessary parameters into equation (2)

the old price per ounce is c/4.

the new price per ounce is c/3.6.

the ratio of the old price to the new one is

(c/4)/(c/3.6) = (c/c)×(3.6/4) = 0.9 . . = 9/10 . . "nine tenths" in either form