A night-light uses 3 W.If the voltage is 120 V, what is the current? A.0.025A B.40 A C.360A D.0.25A

Explain all the energy conversions that take place while using a cell phone.

zhuklara [117]

Answer:

#See solution for details.

Explanation:

-Chemical energy in the battery is converted into Electrical Energy which powers up the phone.

-The electrical energy is then converted to Light Energy when the phone is powered up, this is seen through the lightening up of the phone screen.

-During phone calls, the electrical energy is further converted to Sound Energy to allow for transmission of audio signals.

- As we continue to use the phone, the electrical energy is converted into heat energy which we feel due to an overheating battery.

-The cycle then repeats itself again whenever a phone is charged.

8 0

3 years ago

Light with energy equal to three times the work function of a given metal causes the metal to eject photoelectrons. What is the

Mrac [35]

The ratio of the maximum photoelectron kinetic energy to the work function will be 3:1.

<h3 /><h3>What is the photoelectric effect?</h3>

When a medium receives electromagnetic radiation, electrostatically charged particles are emitted from or inside it.

The emission of ions from a steel plate when light falls on it is a common definition of the effect. The substance could be a solid, liquid, or gas; and the released particles could be protons or electrons.

A particular metal emits photoelectrons when exposed to light with energy three times its work function:

$\rm KE=3 \phi$

The ratio of the maximum photoelectron kinetic energy to the work function will be;

$R=\frac{E}{\phi} \\\\ R=\frac{3 \phi}{\phi} \\\\ R= 3$

Hence, the ratio of the maximum photoelectron kinetic energy to the work function will be 3:1.

To learn more about the photoelectric effect refer to the link;

brainly.com/question/9260704

#SPJ1

5 0

2 years ago

The speed of sound in air is approximately 340 m/s. The speed of light in air is approximately 3 x 108 m/s. If 10 seconds elapse

olya-2409 [2.1K]

Answer:

3400 m

Explanation:

Both lightning and thunder happen at the same time but one is faster than the other. The distance traveled by a sound can be calculated from its speed such that;

speed = distance/time, hence, distance = speed x time.

<em>For a thunder with 340 m/s speed and 10 seconds away from lightning, the distance between the thunder and the lightning can be calculated as</em>;

distance = 340 m/s x 10 s = 3400 m

3 0

3 years ago

How do I convert 14.8 cm into MEters?

stellarik [79]

Multiply it by a fraction equal to ' 1 ', like this:

(14.8 cm) x (1 meter/100 cm) = 14.8/100 = 0.148 meter

6 0

3 years ago

Read 2 more answers

A migrating robin flies due north with a speed of 12 m/s relative to the air. The air moves due east with a speed of 6.7 m/s rel

mafiozo [28]

Here it is given that speed of migrating Robin is 12 m/s relative to air