A small office-building air conditioner operates on 408-V AC and consumes 50.0 kW. (a) What is its effective resistance? (b) What is the cost of running the air conditioner during a hot summer month when it is on 8.00 h per day for 30 days and electricity costs $9.00\ \mathrm{cents/kW} \cdot \mathrm{h} ?$

Which of the following can be a negative consequence of drug use? (a) Temporary euphoria, (b) Decrease in tolerance, (c) Contraction of an STD, (d) Strengthened refusal skills.

Two vehicles start out traveling side by side along a straight road. Their position functions are given by s = f (t) and s = g(t), where s is measured in feet and t is measured in seconds. a. Which vehicle has traveled farther at t = 2 seconds? b. What is the approximate velocity of each vehicle at t = 3 seconds? c. Which vehicle is traveling faster at t = 4 seconds? d. What is true about the positions of the vehicles at t = 4 seconds?

A copper wire has a resistance of 0.500 $\Omega$ at 20.0 $^o$C, and an iron wire has a resistance of 0.525 $\Omega$ at the same temperature. At what temperature are their resistances equal?

What current flows through the bulb of a 3.00-V flashlight when its hot resistance is $3.60 \Omega$?

A window air conditioner that consumes 1 kW of electricity when running and has a coefficient of performance of 3 is placed in the middle of a room, and is plugged in. The rate of cooling or heating this air conditioner will provide to the air in the room when running is (a) 3 kJ/s, cooling (b) 1 kJ/s, cooling (c) 0.33 kJ/s, heating (d) 1 kJ/s, heating (e) 3 kJ/s, heating

A heat engine cycle is executed with steam in the saturation dome. The pressure of steam is 1 MPa during heat addition, and 0.4 MPa during heat rejection. The highest possible efficiency of this heat engine is (a) 8.0% (b) 15.6% (c) 20.2% (d) 79.8% (e) 100%

A North American tourist takes his 25.0-W, 120-V AC razor to Europe, finds a special adapter, and plugs it into 240 V AC. Assuming constant resistance, what power does the razor consume as it is ruined?

If the 0.100-mm diameter tungsten filament in a light bulb is to have a resistance of $0.200\ \Omega$ at $20.0^{\circ} \mathrm{C},$ how long should it be?

What current flows through a 2.54-cm-diameter rod of pure silicon that is 20.0 cm long, when 1.00 $\times$ 10$^3$ V is applied to it? (Such a rod may be used to make nuclearparticle detectors, for example.)

The current supplied to an air conditioner unit is 4.00 amps. The air conditioner is wired using a 10-gauge (diameter 2.588 mm) wire. The charge density is n = 8.48 × 10e28 electrons/m3. Find the magnitude of (a) current density and (b) the drift velocity.

(a) Find the voltage drop in an extension cord having a $0.0600-\Omega$ resistance and through which 5.00 A is flowing. (b) A cheaper cord utilizes thinner wire and has a resistance of $0.300\ \Omega.$ What is the voltage drop in it when 5.00 A flows? (c) Why is the voltage to whatever appliance is being used reduced by this amount? What is the effect on the appliance?

An adiabatic air compressor compresses $10 \mathrm{~L} / \mathrm{s}$ of air at $120 \mathrm{kPa}$ and $20^{\circ} \mathrm{C}$ to $1000 \mathrm{kPa}$ and $300^{\circ} \mathrm{C}$. Find $(a)$ the work needed by the compressor, in $\mathrm{kJ} / \mathrm{kg}$, and (b) the power needed to drive the air compressor, in $k W$.

An adiabatic air compressor compresses 10 L/s of air at 120 kPa and 20$^\circ{}$C to 1000 kPa and 300$^\circ{}$C. Determine (a) the work required by the compressor, in kJ/kg, and (b) the power required to drive the air compressor, in kW.