The picture below shows a wheelbarrow. Using a wheelbarrow can make it easier to lift a heavy object by

A thin film soap bubble (n=1.35) is floating in air. If the thickness of the bubble wall is 300nm, which of the following wavele

iren [92.7K]

Answer:

540 nm

Explanation:

According to the question,

The refractive index of the soap bubble, $n=1.35$ .

The thickness of the soap bubble wall is, $t=300 nm$ .

Now, for constructive interference of soap bubble.

$2nt=(m+\frac{1}{2})\lambda$ .

Now for first order m=1.

Therfore,

$\lambda =\frac{4}{3} tn$

Substitute all the variables in the above equation.

$\lambda =\frac{4}{3} (1.35)(300 nm)$ .

Therefore,

$\lambda =540 nm$ .

Therefore the visible light wavelength which is strongly reflected is 540 nm.

6 0

3 years ago

Which situations might cause two observers (A and B) to measure different frequencies for the same vibrating object? Select the

Alex787 [66]

We want to explain why two different observes may measure different frequencies for the same vibrating object.

We will see that the two correct options are:

Observer A is stationary and Observer B is moving.
Observer A and Observer B are moving at different speeds relative to each other.

Let's assume that the vibrating object is a guitar string. Thus, the string makes a noise, and from that noise, we can estimate the frequency at which the string vibrates.

Now there appears a really cool effect, called the Doppler Effect. It says that the apparent change of frequency is due to the motion of the observer or the source of the frequency (or both).

For example, if you move towards the vibrating string, the perceived frequency will be larger, and you will hear a "higher" sound.

While if you move away from the string, the opposite happens, and you will hear a "lower" sound.

Then the only thing that impacts in how we perceive the frequency is our velocity relative to the source.

So, why do observers A and B measure different frequencies?

The two correct answers are: