All categories

3 years ago

The electric eye that prevents an elevator door from closing when you are in the doorway relies upon which physics principle?

2 answers:

5 0

Just took the test as well that dude is right.. lol I rested my grade in your hands and I got an A.. for more help with that test all answers on here are 100% correct: https://quizlet.com/212791759/1007-unit-10-test-part-1-flash-cards/

goblinko [34]3 years ago

3 0

It's Photoelectric Effect, I just a test with this same question. I am not good for explaining exactly how, but I was right.

You might be interested in

The Netherlands controlled ______ for centuries <br><br> A. Vietnam<br> B. Malaysia<br> C. Indonesia

gogolik [260]

The Netherlands controlled Indonesia for centuries!

4 0

3 years ago

Read 2 more answers

Find the frequency of a wave of wavelength 2.5m and speed 400 m/s

Sedaia [141]

Answer:

The frequency of wave is 160Hz.

Explanation:

Given that the formula of speed is V = f×λ where V represents speed, f is frequency and λ is wavelength.

So first thing, you have to make frequency the subject by dividing wavelength on both sides :

$v = f \times λ \:$

$v \div λ = f \times λ \div λ$

$f = \frac{v}{λ}$

Next you have to substitute the value of v and f into the formula :

Let λ = 2.5m,

Let v = 400m/s,

$f = \frac{400}{2.5}$

$f = 160Hz$

7 0

3 years ago

Q 2 Two mirrors meet at right angles. A ray of light is incident on one at an angle of 30°

serg [7]

a ray of light is incident towards a plane mirror at an angles of 30degrees with the mirror surface. what will be the angles of reflection is 60degree.

3 0

3 years ago

A van moves with a constant speed of 20 miles per hour. How far can it travel in 3 1/2 hours

koban [17]

I think the answer would be 70

5 0

3 years ago

A positively charged sphere with a charge of 8Q is separated from a negatively charged sphere -2Q by a distance r. There is an a

djverab [1.8K]

Answer:

Explanation:

For the first case , the expression for electrostatic force can be given by the following .

F = K x 8Q x 2Q / r² where k is a constant .

F = K 16 Q² / r²

When they touch , some charge is neutralized . Net charge remaining

= 8Q - 2 Q = 6 Q

Charge on each sphere = 6Q/2 = 3 Q .

Force between them

F₁ = k 3Q x 3 Q / r² = k 9 Q² / r²

F₁ / F = 9 / 16

F₁ = 9 F / 16 .

4 0

2 years ago