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2 years ago

Calculate the efficiency of a light bulb that gives 40J of light from 200J of electrical energy’s

Physics

1 answer:

nekit [7.7K]2 years ago

7 0

Answer:

This formula is the most common one used. The efficiency is in a %

20%

Explanation:

Efficiency = energy out / energy in * 100 (for a %)

Efficiency = 40 / 200 * 100

Efficiency = 20%

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Calculate the heat required, in calories, to raise

Goshia [24]

Answer: $Q=4450.74\ J$

Explanation:

Given

mass of tin $m=100 gm$

Also we know that

specific heat of tin $c_{tin}=0.21 J/gm-^{\circ}C$

Melting Point of Tin $T=231.94^{\circ}C$

Heat required to raise the temperature of 100 gm tin is given by

$Q=mc\Delta T$

where $Q=heat\ added$

$c=specific\ heat\ of\ tin$

$\Delta T=change\ in\ temperature$

$Q=100\times 0.21\times (231.94-20)$

$Q=4450.74\ J$

5 0

3 years ago

A 17.0 resistor and a 6.0 resistor are connected in series with a battery. The potential difference across the 6.0 resistor is m

tia_tia [17]

Answer:

V= 57.5 V

Explanation:

If the resistors are in the linear zone of operation, the potential difference across them, must obey Ohm's law:

$V = I*R$

For the 6.0 Ω resistor, if the potential difference across it is 15 V, we can find the current flowing through it as follows:

$I = \frac{V}{R} = \frac{15 V}{6.0 \Omega} = 2.5 A$

In a series circuit, the current is the same at any point of it, so the current through the battery is I = 2.5 A
The equivalent resistance of a series circuit is just the sum of the resistances, so, in this case, we can write the following equation:

$R_{eq} = R_{1} +R_{2} = 17.0 \Omega + 6.0 \Omega = 23.0 \Omega$

Applying Ohm's Law to the equivalent resistance, we can find the potential difference through it, that must be equal to the potential difference across the battery, as follows:

$V = I* R_{eq} = 2.5 A * 23.0 \Omega = 57.5 V$

8 0

3 years ago

What is potential energy

JulsSmile [24]

Answer:

An Energy held by an object because of its position relative by other objects

Explanation:

6 0

3 years ago

What role does the somatic nervous system play?

kodGreya [7K]

Explanation:

The somatic nervous system coordinates the voluntary control of movement in the body system.

The nervous system is made up of the central nervous system and peripheral nervous system.

The peripheral nervous system is made up of the nerves that branches into the body from the spinal cord.

It consist of the somatic nervous system and the autonomous nervous system.
The somatic nervous system controls the voluntary actions of movement in the body.
It coordinates the reflex arc.

Learn more:

Nervous system brainly.com/question/4662759

#learnwithBrainly

4 0

3 years ago

In the Hunger Games movie, Katniss Everdeen fires a 0.0200-kg arrow from ground level to pierce an apple up on a stage. The spri

egoroff_w [7]

Answer:

a) $v=99.8584\ m.s^{-1}$

b) $v'=99.366\ m.s^{-1}$

Explanation:

Given:

mass of the arrow, $m=0.02\ kg$

stiffness constant of the bow, $k=330\ N,m^{-1}$

distance of pulling back the arrow on the bow from its mean position, $\Delta x=0.55\ m$

height of the apple targeted, $h=5\ m$

<u>Force on the arrow due to the stiffness of the bow:</u>

$F=k.\Delta x$

$F=330\times 0.55$

$F=181.5\ N$

Now the acceleration of the arrow upwards:

$a=\frac{F}{m}$

$a=\frac{181.5}{0.02}$

$a=9075\ m.s^{-2}$

a) For the course of motion when the arrow leaves the bow after the stretch is relaxed we consider that the arrow left the bow after its string goes to the mean position. During this phase the arrow also faces gravity in the downward direction.

Using the equation of motion:

$v^2=u^2+2(a-g).\Delta x$