Answer:
g' = 10.12m/s^2
Explanation:
In order to calculate the acceleration due to gravity at the top of the mountain, you first calculate the length of the pendulum, by using the information about the period at the sea level.
You use the following formula:
(1)
l: length of the pendulum = ?
g: acceleration due to gravity at sea level = 9.79m/s^2
T: period of the pendulum at sea level = 1.2s
You solve for l in the equation (1):

Next, you use the information about the length of the pendulum and the period at the top of the mountain, to calculate the acceleration due to gravity in such a place:

g': acceleration due to gravity at the top of the mountain
T': new period of the pendulum

The acceleration due to gravity at the top of the mountain is 10.12m/s^2
A parachute is a device designed to generate a LOT of air resistance.
Parachutes do that very well in places where there's any air to work with.
There is no air on the Moon.
Answer:
The force has been reduced by 8018 N
Explanation:
The impulse exerted on the car during the crash is equal to the product of the force exerted and the duration of the collision, and it is also equal to the change in momentum of the car. So we can write:

where:
F is the force exerted on the car
is the duration of the collision
m = 1400 kg is the mass of the car
is the change in velocity of the car
We can re-write the equation as

In the 1st collision, the time is 1.5 seconds, so the force is

In the 2nd collision, the time is increased to 2.2 seconds, so the force is

Therefore, the force has been reduced by:

Explanation:
Suppose you want to shine a flashlight beam down a long, straight hallway. Just point the beam straight down the hallway -- light travels in straight lines, so it is no problem. What if the hallway has a bend in it? You could place a mirror at the bend to reflect the light beam around the corner. What if the hallway is very winding with multiple bends? You might line the walls with mirrors and angle the beam so that it bounces from side-to-side all along the hallway. This is exactly what happens in an optical fiber.
The light in a fiber-optic cable travels through the core (hallway) by constantly bouncing from the cladding (mirror-lined walls), a principle called total internal reflection. Because the cladding does not absorb any light from the core, the light wave can travel great distances.
However, some of the light signal degrades within the fiber, mostly due to impurities in the glass. The extent that the signal degrades depends on the purity of the glass and the wavelength of the transmitted light (for example, 850 nm = 60 to 75 percent/km; 1,300 nm = 50 to 60 percent/km; 1,550 nm is greater than 50 percent/km). Some premium optical fibers show much less signal degradation -- less than 10 percent/km at 1,550 nm.
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