Here's a great everyday use of the physics described in think about what subsequently happens to the ketchup, which is initially at rest, and use newtons first law to explain why this technique is so successful this chapter. if you are trying to get keichup out of the bottle, the best way to do it is to turn the bottle upside down and give the bottie a sharp upward smack, forcing the bottle rapidly upward. (figure 1 the weight of the ketchup will keep it from moving if you give the bottle a sharp upward smack figure the static friction of the ketchup wil keep it from moving if it isnt too tightly adhered to the sides of the moving bottle of1 the inertia of the ketchup will keep it from moving if it isn't too tightly adhered to the sides of the moving bottle. the kinetic friction of the ketchup will keep it from moving if it isn't too tightly adhered to the sides of the moving bottle

"The static friction of the ketchup wil keep it from moving if it isnt too tightly adhered to the sides of the moving bottle"

Explanation:

We want to see why is that the ketchup does not move of the bottom of the bottle when we want to use it.

The options are:

Because of the weight.

Because of the static friction.

Because of the inertia.

Because of the kinetic friction.

First, we can discard weight and inertia, because these two things actually help to get the ketchup out of the bottle.

The remaining options are static friction and kinetic friction:

If the kinetic friction has an effect, it means that the ketchup inside the bottle is moving, so this option can also be discarded.

Then the correct option is static friction, which the ketchup does against the walls of the bottle and keeps it in place.

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.