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3 days ago

160 students sit in an auditorium listening to a physics lecture. Because they are thinking hard, each is using 125 W of metabol

ic power, slightly more than they would use at rest. An air conditioner with a COP of 5.0 is being used to keep the room at a constant temperature.
what minimum power should be used to operate the air conditioner?

Physics

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Which, if any, of the following statements concerning the work done by a conservative force is NOT true? All of these statements

Yuliya22 [3333]

Answer:

If the starting and ending points are identical, the overall work equals zero.

Explanation:

Option (D) is correct.

A force is considered conservative when the work performed by it while moving an object from point A to point B does not rely on the path taken and remains consistent across all paths. The work done is determined solely by the initial and final locations of the particle. Thus, when the initial and final positions in a conservative field coincide, the work is said to be zero.

8 0

3 months ago

A 450g mass on a spring is oscillating at 1.2Hz. The totalenergy of the oscillation is 0.51J. What is the amplitude.

Sav [3153]

Response:

A=0.199

Clarification:

We know that

Mass of spring=m=450 g= $=\frac{450}{1000}=0.45 kg$

Where 1 kg=1000 g

Frequency of oscillation=

$\nu=1.2Hz$

Energy for oscillation is 0.51 J

To determine the amplitude of oscillations.

Energy for oscillator= $E=\frac{1}{2}m\omega^2A^2$

Where $\omega=2\pi\nu$ =Angular frequency

A=Amplitude

$\pi=\frac{22}{7}$

Using the formula

$0.51=\frac{1}{2}\times 0.45(2\times \frac{22}{7}\times 1.2)^2A^2$

$A^2=\frac{2\times 0.51}{0.45\times (2\times \frac{22}{7}\times 1.2)^2}=0.0398$

$A=\sqrt{0.0398}=0.199$

Therefore, the amplitude of oscillation=A=0.199

4 0

2 months ago

A glass tube is filled with hydrogen gas. An electric current is passed through the tube, and the tube begins to glow a pinkish

inna [3103]

The initial description is the accurate one.

6 0

3 months ago

Read 2 more answers

The height of a typical playground slide is about 6 ft and it rises at an angle of 30 ∘ above the horizontal.

Maru [3345]

Answer:

The coefficient of kinetic friction is found to be 0.432.

Explanation:

Comprehensive steps and derivations with necessary substitutions are detailed in the attached document.

6 0

3 months ago

A supersonic nozzle is also a convergent–divergent duct, which is fed by a large reservoir at the inlet to the nozzle. In the re

Softa [3030]

Answer:

155.38424 K

2.2721 kg/m³

Explanation:

$P_1$ = Reservoir pressure = 10 atm

$T_1$ = Reservoir temperature = 300 K

$P_2$ = Exit pressure = 1 atm

$T_2$ = Exit temperature

$R_s$ = Specific gas constant = 287 J/kgK

$\gamma$ = Specific heat ratio = 1.4 for air

Assuming isentropic flow

$\frac{T_2}{T_1}=\frac{P_2}{P_1}^{\frac{\gamma-1}{\gamma}}\\\Rightarrow T_2=T_1\times \frac{P_2}{P_1}^{\frac{\gamma-1}{\gamma}}\\\Rightarrow T_2=00\times \left(\frac{1}{10}\right)^{\frac{1.4-1}{1.4}}\\\Rightarrow T_2=155.38424\ K$

Flow temperature at exit is 155.38424 K

Density at exit can be derived using the ideal gas equation

$\rho_2=\frac{P_2}{R_sT_2}\\\Rightarrow \rho=\frac{1\times 101325}{287\times 155.38424}\\\Rightarrow \rho=2.2721\ kg/m^3$

Flow density at exit measures 2.2721 kg/m³

4 0

3 months ago