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3 years ago

Can someone help me please it is number 7

Physics

1 answer:

motikmotik3 years ago

4 0

D. The string vibrated because of resonance, which happened because the tuning fork and guitar string have same natural frequency.

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Pls help me its due today

poizon [28]

Answer:

pls give me brainliest

Explanation:

3 0

3 years ago

Which is classified as an inner transition element

slamgirl [31]

An inner transition metal (ITM) is one of a group of chemical elements on the periodic table. They are normally shown in two rows below all the other elements. They include elements 57-71 (lanthanides) and 89-103 (actinides).

7 0

3 years ago

Recall from Chapter 1 that a watt is a unit of en- ergy per unit time, and one watt (W) is equal to one joule per second ( J·s–1

harkovskaia [24]

Answer:

Explanation:

The energy of a photon is given by the equation $E_p=h f$ , where h is the <em>Planck constant</em> and f the frequency of the photon. Thus, N photons of frequency f will give an energy of $E_N=N h f$ .

We also know that frequency and wavelength are related by $f=\frac{c}{\lambda}$ , so we have $E_N=\frac{N h c}{\lambda}$ , where c is the <em>speed of light</em>.

We will want the number of photons, so we can write

$N=\frac{\lambda E_N}{h c}$

We need to know then how much energy do we have to calculate N. The equation of power is $P=E/t$ , so for the power we have and considering 1 second we can calculate the total energy, and then only consider the 4% of it which will produce light, or better said, the N photons, which means it will be $E_N$ .

Putting this paragraph in equations:

$E_N=(\frac{4}{100})E=0.04Pt=(0.04)(100W)(1s)=4J$ .

And then we can substitute everything in our equation for number of photons, in S.I. and getting the values of constants from tables:

$N=\frac{\lambda E_N}{h c}=\frac{(520 \times10^{-9}m) (4J)}{(6.626\times10^{-34}Js) (299792458m/s)}=1.047 \times10^{19}$

3 0

3 years ago

Which explanation of the solar system best fits the observations of the planets and how they orbit the sun?

NeTakaya

You're right, Answer C

The dust and gas accumulate to form a solar nebula, which later on creates the star and the planets.

4 0

3 years ago

Read 2 more answers

A car travels around a level, circular track that is 750m across. What coefficient of friction is required to ensure the car can

Crank

The coefficient of friction must be 0.196

Explanation:

For a car moving on a circular track, the frictional force provides the centripetal force needed to keep the car in circular motion. Therefore, we can write:

$\mu mg = m\frac{v^2}{r}$

where the term on the left is the frictional force acting between the tires of the car and the road, while the term on the right is the centripetal force. The various terms are:

$\mu$ is the coefficient of friction between the tires and the road