All categories

2 years ago

9. How much energy does a 100 W light bulb use in half an hour? If the light bulb converts

1 answer:

6 0

The energy used by the light bulb in half an hour is 180000 J and the amount of thermal energy generated is 158400 J.

What is Energy?

Energy is the ability or the capacity to do work.

To calculate the energy of the light bulb we use the formula below

Formula:

E = Pt.......... Equation 1

Where:

E = Energy used by the bulb in a half-hour
P = Power of the bulb
t = Time

Given:

P = 100 W
t = 1/2 hour = 30 minutes = (30×60) = 1800 seconds

Substitute these values into equation 1

E = (100×1800)
E = 180000 J

If the light converts 12% of electric energy to light energy, then 88% of the energy is used to generate thermal energy

Therefore,

Thermal energy = (180000×88/100) = 158400 J

Hence, the energy used by the light bulb in half an hour is 180000 J and the amount of thermal energy generated is 158400 J.

Learn more about energy here: brainly.com/question/21927255

#SPJ1

You might be interested in

Kinetic and potential; what type of energy is each of the points

miskamm [114]

Answer:

1 potential

2 kenitic

3 kenitic

4 potential

5 kenitic

6 potential

7 0

3 years ago

If two swimmers compete in a race, does the faster swimmer develop more power?

valkas [14]

Power is equal to energy per unit time. In this case, power is proportional to energy while is inversely proportional to time,on the other hand. Given the two swimmers exerts same amount of energy but the faster swimmer just does things in faster time, then the faster swimmer should develop more power from shorter time

7 0

3 years ago

What do you think we can learn about Earth's history by looking at the Grand Canyon?

viktelen [127]

We can look at all the ages of the earth since it’s a big crack is reveals many layers of the earth and we can know about chemicals and metals that were in earth and diffrent times

5 0

3 years ago

Alpha particles, each having a charge of +2e and a mass of 6.64 ×10-27 kg, are accelerated in a uniform 0.50 T magnetic field to

sergij07 [2.7K]

Answer:

$KE=1.2036\times 10^{-12}\ J$

Explanation:

Given:

charge on the alpha particle, $q=2e=3.2\times 10^{-19}\ C$

mass of the alpha particle, $m=6.64\times 10^{-27}\ kg$

strength of a uniform magnetic field, $B=0.5\ T$

radius of the final orbit, $r=0.5\ m$

<u>During the motion of a charge the magnetic force and the centripetal forces are balanced:</u>

$q.v.B=m.\frac{v^2}{r}$

$m.v=q.B.r$

where:

v = velocity of the alpha particle

$v=\frac{q.B.r}{m}$

$v=\frac{3.2\times 10^{-19}\times 0.5\times 0.5}{6.64\times 10^{-27}}$

$v=1.2048\times 10^{7}\ m.s^{-1}$

Here we observe that the velocity of the aprticle is close to the velocity of light. So the kinetic energy will be relativistic.

<u>We firstly find the relativistic mass as:</u>

$m'=\frac{1}{\sqrt{1-\frac{v^2}{c^2} } } \times m$

$m'=\frac{6.64\times 10^{-27}}{\sqrt{1-\frac{(1.2048\times 10^7)^2}{(3\times 10^8)^2} } }$

$m'=6.6533\times10^{-27}\ kg$

now kinetic energy:

$KE=m'.c-m.c$

$KE=6.6533\times 10^{-27}\times (3\times 10^8)^2-6.64\times 10^{-27}\times (3\times 10^8)^2$

$KE=1.2036\times 10^{-12}\ J$

6 0

3 years ago

"when light travels from air into a piece of glass, a change in direction may occur. what is the name of this phenomenon

Kaylis [27]

As light travels through a medium, it moves in a straight line path,but when light passes from one medium into another medium, the light path bends,Refraction takes place.

8 0

3 years ago

Read 2 more answers