A complex arrangement of pulleys forms what is called the block in a block and tackle. The rope used to lift the pulleys and the load is the tackle. A block and tackle is used to lift a truck engine, which has a weight and output force of nearly 8000 N. The input force required to lift this weight using the block and tackle is 400N. What is the mechanical advantage of the block and tackle?

Mechanical advantage = 20

Explanation:

Given:

Output force = 8,000 N

Input force = 400 N

Find:

Mechanical advantage

Computation:

Mechanical advantage = Output force / Input force

Mechanical advantage = 8,000 / 400

Mechanical advantage = 20

the closer the planet is to the sun, the larger the gravity

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.