A gas is contained in a vertical, frictionless piston-cylinder device. The piston has a mass of 3.2 kg and a cross-sectional area of 35 cm2. A compressed spring above the piston exerts a force of 110 N on the piston. If the atmospheric pressure is 95 kPa, determine the pressure inside the cylinder.

146.826 KPa

Explanation:

Given:

The mass of the piston = 3.2 kg

Cross-sectional area = 35 cm²

Force exerted by the spring = 110 N

Atmospheric pressure = 95 KPa

Now,

the total pressure inside the cylinder is the sum of all the pressure exerted on it i, e the pressure due the weight of the piston, pressure due to the force by the spring and the atmospheric pressure.

Now,

the pressure due to the weight of the piston = Weight / Area

= 3.2 * 9.81 / 0.0035

= 31.392 / 0.0035

= 8969 Pa

= 8.969 KPa

And,

The pressure by the spring = 150 N / 0.0035

or

The pressure by the spring = 42,857 Pa = 42.857 KPa

Thus,

The total pressure

95 + 8.969 + 42.857 = 146.826 KPa