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3 years ago

How do you find input energy with only the efficiency and output energy given?

Physics

1 answer:

iris [78.8K]3 years ago

8 0

Answer:

power output/transformer efficiency multiply by 100%

Explanation:

derrive the formula from efficiency=power output/power input multiply by 100%

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What will be the ME of a machine that produces a 240 N work with a 300

Elden [556K]

Answer:

Efficiency = 80%

Explanation:

Given the following data;

Work output = 240 N

Work Input = 300 N

To find the mechanical efficiency of a machine;

$Efficiency = \frac {Out-put \; work}{In-put \; work} * 100$

Substituting into the equation, we have;

$Efficiency = \frac {240}{300} * 100$

$Efficiency = 0.8 * 100$

Efficiency = 80%

Therefore, the mechanical efficiency of the machine is 80 percent.

3 0

3 years ago

Chapter 16, Problem 63. A person is standing in a room at 18 ◦C. The exposed surface area and skin temperature of the person are

Juliette [100K]

Answer: $Q=248.011 W$

Explanation:

Given

Temperature of Room $T_{\infty }=18^{\circ}\approx 291 K$

Area of Person $A=1.7 m^2$

Temperature of skin $T=32^{\circ}\approx 305 K$

Heat transfer coefficient $h=5 W/m^2.k$

Emissivity of the skin and clothes $\epsilon =0.9$

$\Delta T=32-18=14^{\circ}$

Total rate of heat transfer=heat Transfer due to Radiation +heat transfer through convection

Heat transfer due radiation $Q_1=\epsilon \sigma A(T^4-T_{\infty }^4 )$

where $\sigma =stefan-boltzman\ constant$

$Q_1=0.9\times 5.687\times 10^{-8}\times 1.7\times (305^4-291^4)$

$Q_1=129.01 W$

Heat Transfer due to convection is given by

$Q_2=hA(\Delta T)$

$Q_2=5\times 1.7\times 14=119 W$

$Q=Q_1+Q_2$

$Q=129.01+119=248.011 W$

7 0

3 years ago

A spring stretches 5 cm when a 300-N mass is suspended from it. Calculate the spring constant in N / m .

rusak2 [61]

Answer:

Spring constant in N / m = 6,000

Explanation:

Given:

Length of spring stretches = 5 cm = 0.05 m

Force = 300 N

Find:

Spring constant in N / m

Computation:

Spring constant in N / m = Force/Distance

Spring constant in N / m = 300 / 0.05

Spring constant in N / m = 6,000

8 0

2 years ago

C. A helium atom has a diameter of approximately 9.8 • 10-11 meters. What is the diameter of a helium atom in nanometers? Given

Studentka2010 [4]

$1\ nm = 10^{-9} m\\\\1\ m =\frac{1\ nm}{10^{-9}}$

Since the diameter of helium atom is approximately $9.8\times 10^{-11}\ m$ , therefore the diameter of helium atom in nano meter,

$9.8\times 10^{-11}\ m=9.8\times 10^{-11} \times\frac{1\ nm}{10^{-9}}=0.098\ nm$

4 0

3 years ago

What is the effect on the force of gravity between two objects if the mass of one object doubles?

Leni [432]

Then the force will also be doubled

6 0

3 years ago