In a physics lab, light with a wavelength of 530 nm travels in air from a laser to a photocell in a time of 16.7 ns . When a slab of glass with a thickness of 0.870 m is placed in the light beam, with the beam incident along the normal to the parallel faces of the slab, it takes the light a time of 21.3 ns to travel from the laser to the photocell.

What is the wavelength of the light in the glass?

Use 3.00×108 m/s for the speed of light in a vacuum. Express your answer using two significant figures.

Explanation:

Given:

Now we have the relation for time:

hence,

c= speed of light in air

For the case when glass slab is inserted between the path of light:

(since light travel with the speed c only in the air)

here:

v = speed of light in the glass

Using Snell's law:

She is likely to crash because her flight gradient is lesser than the flight gradient required gradient to avoid crashing

Explanation:

The given parameters are;

The required gradient of the plane Ashley is flying needs to reach in order to take off and not crash = 360 m/km

The initial elevation of the plane Ashley is flying = Sea level = 0 m

The goal Ashley intends to make = Elevation of 1000 m at 2.8 km. distance

∴ Ashley's goal = Traveling from sea level to 1000 m at 2.8 km horizontal distance

We have;

The gradient  = Rate of change of elevation/(Horizontal distance)

Therefore;

The gradient of Ashley's flight = (1000 - 0)/(2.8 - 0) = 357.143 m/km

The gradient of Ashley's flight ≈ 357.143 m/km which is lesser than the required 360 m/km in order to take off and not crash, therefore, she will crash.