piston whose area is 60 cm2 moves through a distance of 20 cm against a pressure of 3 atm. calculate the work done in joules and calories

Answer 1

First, let's convert the pressure from atm to pascals (Pa):

1 atm = 101325 Pa

3 atm = 3 * 101325 = 303975 Pa

Next, we have to convert the area from cm² to m²:

60 cm² = 0.006 m² (divide by 10000)

Now, let's find the volume that the piston moves through:

Volume (V) = Area (A) * Distance (d)
V = 0.006 m² * 20 cm = 0.006 m² * 0.2 m = 0.0012 m³ (multiply by 0.01 to convert from cm to m)

The work (W) done by the piston can be calculated using the formula:

W = -P * ΔV

Where P is the pressure and ΔV is the change in volume.

W = -303975 Pa * 0.0012 m³ = -364.77 J

The work done is -364.77 Joules. The negative sign indicates that the work is done against the pressure.

To convert the work done in Joules to calories, use the conversion factor:

1 calorie (cal) = 4.184 Joules (J)

W = -364.77 J * (1 cal / 4.184 J) ≈ -87.2 cal

The work done is approximately -87.2 calories.