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3 years ago

A. How long does it take light to travel through a 3.0-mm-thick piece of window glass?

Physics

1 answer:

hodyreva [135]3 years ago

6 0

Answer:

a) $1.517\times10^{-11}$ s

b) 3.41 mm

Explanation:

We take the speed of light, c = $3.0\times10^8$ m/s and the refractive index of glass as 1.517.

Speed = distance/time

Time = distance/speed

Refractive index, n = speed of light in vacuum / speed of light in medium

$n=\dfrac{c}{s}$

$s=\dfrac{c}{n}$

$t=\dfrac{d}{c/n}$

$t=\dfrac{dn}{c}$

$t=\dfrac{3\times10^{-3}\times1.517}{3.0\times10^8}$

$t=1.517\times10^{-11}$

We take the refractive index of water as 1.333.

Speed in water = speed in vacuum / refractive index of water

Distance = speed * time

$d=s\times t$

$d=\dfrac{c}{n_w}\times \dfrac{3\times10^{-3}\times1.517}{c}$

$d=\dfrac{3\times10^{-3}\times 1.517}{1.333}$

d = 3.41 mm

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Answer:

Explanation:

The guy wire is making a right angled triangle with the ground and stop sign . It makes an angle of 51 degree with the ground. In this triangle stop sign is the perpendicular and distance from the base on the ground forms the base of the triangle . Wire forms the hypotenuse.

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2 years ago

Consider the following statements. A. Heat flows from an object at higher temperature to an object at lower temperature; B. Heat

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Answer:

A. Heat flows from an object at higher temperature to an object at lower temperature

Explanation:

The option A obeys the 2nd law of thermodynamics. The heat will flow from the object at higher temperature to the object at Lower temperature till they reach an equilibrial state.

Heat doesn’t necessarily flow from an object with higher thermal energy to an object with lower thermal energy because an object has a higher thermal energy when it’s mass is more than the other. This makes B wrong.

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2 years ago

Discuss how the hardness or softness of the landing surface is related to the time required to stop the egg

monitta

Answer

To understand this concept it is necessary to understand Newton's Second Law

According to Newtons Second law applied force is equal to rate of change of momentum of a body.

Mathematically,

$F=\frac{dp}{dt}$

here, $\frac{dp}{dt}$ is rate of change of momentum with respect to time

It means If two eggs fall from same height,one on softer surface and other on hard surface that time the momentum of both eggs will remain equal at both the surfaces. But, impact time will be different. On hard surface egg will stop almost instantly so impact time will be small and hence the force on egg will be large therefore the egg will breakup.

On the other hand on the soft surface like a cotton, egg will not stop instantly but it will slow down for a few seconds and then stop due to which the time of impact will increase. Therefore the force on egg will be less and it won't break up.

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3 years ago

The following situation will be used for the next three problems: A rock is projected upward from the surface of the moon, at ti

chubhunter [2.5K]

Explanation:

Given that,

Initial speed of the rock, u = 30 m/s

The acceleration due to gravity at the surface of the moon is 1.62 m/s².

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The rock is projected from the surface of the moon. The equation of motion in this case is given by :

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2 years ago