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Brilliant_brown [7]

3 years ago

14

A bulb converts 9J of energy in each second from an input of 100J of energy. Calculate efficiency of this light bulb

1 answer:

77julia77 [94]3 years ago

8 0

Efficiency is calculated through dividing the actual mechanical advantage by the hypothetical mechanical advantage:

- the actual mechanical advantage is 9J because that's how much work the light bulb doing

- the hypo. mechanical advantage is 100J. Ideally, in a perfect world, the light bulb can convert 100J input into 100J output, but do to resistance and other factors it is not possible.

$\frac{9}{100} = .09$
change the decimal to a percentage:

$.09 = 9\%$
the light bulb had 9% efficiency

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The answer to the question

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A generator uses a coil that has 100 turns and a 0.50-T magnetic field. The frequency of this generator is 60.0 Hz, and its emf

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Answer:

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Explanation:

Number of turns=N=100

Magnetic field=B=0.50 T

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We have to find the length of the wire from which the coil is made.

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6 0

2 years ago

In a simple RC circuit, at t=0 the switch is closed with the capacitor uncharged. If C=30µF, =50V and R=10k, what is the poten

sergij07 [2.7K]

Answer:

Voltage across the capacitor is 30 V and rate of energy across the capacitor is 0.06 W

Explanation:

As we know that the current in the circuit at given instant of time is

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now we know by ohm's law

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$V = (2 mA)(10 kohm)$

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so voltage across the capacitor + voltage across resistor = V

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$V_c = 30 V$

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here rate of change in energy of the capacitor is given as

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A stone is thrown at an angle of 30 degrees above the horizontal from the top edge of a cliff with an initial speed of 12 m/s. A

natta225 [31]

v = initial velocity of launch of the stone = 12 m/s

θ = angle of the velocity from the horizontal = 30

Consider the motion of the stone along the vertical direction taking upward direction as positive and down direction as negative.

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a = acceleration of the stone = - 9.8 m/s²

t = time of travel = 4.8 s

Y = vertical displacement of stone = vertical height of the cliff = ?

using the kinematics equation

Y = v₀ t + (0.5) a t²

inserting the values

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