Physics Answers

The property relation (pu/RT) = Z is known as the compressibility factor for a given substance. For an ideal gas, Z = 1 at any state. (a) Find the compressibility factor Ze for a van der Waals gas at the critical point. (b) Using this value of Ze, rewrite the expressions for the constants a and b ex cluding the property v.

Show that the fugacity of a van der

Waals gas is given by the expression.

In f = -In (v-b) - 2a/RTV + b/v-b

Saturated steam at 200 bar is to be heated at constant pressure to 650°C. Using appropriate deviations, determine ∆h, the heat added, ∆s, and the specific volume at state 2. Compare results with values read from the Mollier chart, Item B 16 (SI).

Find the density of air at 13.79 MPaa and 172.8 K, using (a) pv = RT, (5) pv = ZRT, (c) van der Waals equation. (d) Which of the three answers do you believe is more accurate?

Nitrogen is stored in a 0.425 m² tank at 560 atm, 456 K. Determine the mass of nitrogen in the tank using (a) ideal gas theory, (b) the compressibility factor, (c) van der Waals equation.

1.    An ideal Otto cycle has a compression ratio of 7. At the beginning of the compression

process, air is at 107 kPa and 19°C, and 750 kJ/kg of heat is transferred to air during

the constant-volume heat-addition process. Accounting for the variation of specific

heats of air with temperature, determine (a) the maximum temperature and pressure

that occur during the cycle, (b) the net work output, (c) the thermal efficiency, and

(d) the mean effective pressure for the cycle.

(e) Also, determine the power output from the cycle, in kW, for an engine speed

of 3700 rpm (rev/min). Assume that this cycle is operated on an engine that has four

cylinders with a total displacement volume of 1.9 L.

one mole of an ideal monoatomic gas is taken through the cycle shown in the figure.

the process A:B is a reversible isothermal expansion.

Given. P(A)=5atm V(A)=10litre

P(B)=1atm V(B)=50litre

P(C)=1atm V(C)=10litre

a.calculate the net work done by the gas

b.the energy added to the gas.

c.the energy expelled by the gas.

d.the efficiency of the cycle.

A neutron in a reactor makes an elastic headon collision with the nucleus of an atom initially at rest. Assume: The mass of the atomic nucleus is about 11.3 the mass of the neutron. What fraction of the neutron’s kinetic energy is transferred to the atomic nucleus?

The body accelerates uniformly from 33m/s. Find it's velocity after travelling a distance from 24m.

A train with an intial velocity of 20m/s is subjected to a uniform deceleration of 2m/s. Calculate the time required to bring the train to a complete halt.