Answer:
see below
Explanation:
refractive index of a medium is defined as the ratio of the speed of light in vacuum to the speed of light in medium
critical angle of glass is 42 means that if the angle of incidence inside the glass is 42 degrees, then the angle of refraction in the optically less dense medium will be 90 degrees
hope this helps
Answer:
The towers height is 322m
Explanation:
We can assume that a simple pendulum hangs from the top of the tower.
In this case, the length of the pendulum will be the same as the height of the tower.
We will use the next expression then:

Where T is the period, L is the pendulum length and g is the gravity 
From the previous expression we will have then that the length will be:

Replacing:

The towers height will be then: 322m
Answer:(of a reaction or process) accompanied by the release of heat.
Explanation: trust moi
Answer:
Speed = 0
Restoring force = maximum
Explanation:
Suppose this situation as a spring with a mass attached to it, that oscilates.
The force that the spring does (the restoring force in this case) is something like
F = K*L
where K is the constant of the spring, and L is the difference between the length of the spring (stretched) and the length of the spring at rest.
Then, when the harmonic oscillator is at its maximum displacement, L takes its maximum value, which means that at this point the restoring force must also have a maximum.
And for the velocity, at this point we have the maximum displacement, this means that, if the mass was moving to the right, after this point the mass stops going to the right, and then returns to the equilibrium position to the left.
Then the velocity has a change of sign, (like an object that reached its maximum height) this means that at that exact moment, the velocity must be zero.
Then:
Speed = 0
Restoring force = maximum