Molecular Physics | Thermodynamics Answers

. A concrete highway is built of slabs 12 m long (20°C). How wide should the
expansion cracks between the slabs be (at 20°C) to prevent buckling if the range of
temperature is -30°C to +50°C?

Fluid of density 2700 kg m−3 flows through a horizontal pipe that curves up into a vertical pipe as shown as shown in the figure above. If the absolute pressure in the pipe at point 1 is P1 = 160 kPa then what is the absolute pressure in the pipe at point 2, P2 (A= 0.067cm^2 H= 52cm

(a) What is the average translational kinetic energy of an ideal-gas molecule at 27°C?
(b) What is the total random translational kinetic energy of the molecules in 1 mole of this gas?
(c) What is the root-mean-square speed of oxygen molecules at this temperature?

Compute the frequency (in MHz) of an EM wave with a wavelength of 9.0 in. (0.2286 m).

The blackbody radiation emitted from a furnace peaks at a wavelength of 7.0 10-6 m (0.0000070 m). What is the temperature inside the furnace?

The generator at a power plant produces AC at 25,000 V. A transformer steps this up to 355,000 V for transmission over power lines. If there are 2,150 turns of wire in the input coil of the transformer, how many turns must there be in the output coil?

An electric clothes dryer is rated at 4,800 W. How much energy does it use in 50 min?

All of the electrical outlets in a room are connected in a single parallel circuit. The circuit is equipped with a 20-A fuse, and the voltage is
V = 220 V.

(a) What is the maximum total power that can be supplied by the outlets without blowing the fuse?



(b) How many 2,300-W appliances can be plugged into the sockets without blowing the fuse?

The resistance of each brake lightbulb on an automobile is
4.0 Ω.
Use the fact that cars have 12-V electrical systems to compute the current that flows in each bulb if they are connected in series. (For simplicity, assume that the circuit is only composed of one brake lightbulb and the car battery.)

Select all of the following descriptions that match what happens when a ferromagnetic material is placed in an external magnetic field.

The ferromagnetic material rapidly cools.
The ferromagnetic material becomes negatively charged.
The ferromagnetic material becomes positively charged.
The external magnetic field induces magnetic poles in the ferromagnetic material.
The ferromagnetic material becomes magnetized.
Nothing, ferromagnetic materials do not interact with magnetic fields.