In the Balmer series, how many spectral lines have the wavelength greater than 400 nm?

Answer: shrink and heat

Stars similar to our Sun use hydrogen as fuel, creating helium in the process of nuclear fusion.

Now when the hydrogen is used up, the core of the star reaches such a temperature that begins to transform the helium into carbon. That is, the core heats up more due to the continuous fusion reactions and shrinks because it will not have enough pressure to maintain its size.

Technically, there is not enough information to tell, because in your picture, you cut off the last word in the question.

If the last word in the question is "acceleration", then "C" is the correct choice.

If some other word is the last one in the question, then it has to be "D".

Answer:

D. there is not enough information to tell

Explanation:

I have already read this in grade five

By using the relation between period and frequency, we conclude that the period of the fork is0.0023 seconds.

What is the period of the vibrating fork?

We know that the relation between period and frequency is:

T = 1/f

where T is the period and f is the frequency.

In this case, we know that the frequency of the fork is 440 Hz, where:

1 Hz = 1/s

Then the period of the fork will be:

T = 1/(440 Hz) = (1/440) s = 0.0023 s

Meaning that each complete vibration of the fork takes 0.0023 seconds.

If you want to learn more about waves, you can read:

brainly.com/question/15531840

The rate at which the voltage of the given circuit is changing is gotten to be;

dV/dt = 0.452 V/s

We are given;

Current; I = 3 A

Resistance 1; R1 = 4Ω

Resistance 2; R2 = 3Ω

dR1/dt = 0.4 Ω/s

dR2/dt = 0.2 Ω/s

dI/dt = 0.02 A/s

Now, formula for voltage with resistors in parallel is;

1/V = (1/I)(1/R1 + 1/R2)

Plugging in the relevant values, we can find V;

1/V = (1/3)(1/4 + 1/3)

Simplifying this gives;

1/V = 0.194

Now, we want to find the rate at which the voltage is charging, we need to find dV/dt.

Thus, let us differentiate 1/V = (1/I)(1/R1 + 1/R2) with respect to t to get;

(1/V)²(dV/dt) = [(1/i²)(di/dt)(1/R1 + 1/R2)] + (1/I)[(1/R1²)(dR1/dt) + (1/R2²)(dR2/dt)]

Plugging in the relevant vies gives us;

0.194²(dV/dt) = [(1/3²)(0.02)(¼ + ⅓)] + (⅓)[(1/3²)(0.4) + (1/4²)(0.3)]

>> 0.037636(dV/dt) = 0.001296 + 0.0157

>> dV/dt = 0.016996/0.037636

>> dV/dt = 0.452 V/s

Read more at; brainly.com/question/13539417

Answer:

Explanation:

As we know that two resistors are in parallel

so we have

where we know that

so we have

now to find the rate of change we have

now from above equation we have