Aperson pushes a crate up a 4-m high ramp for a distance of 18m.

a) what is the mechanical advantage of the ramp?

b) how hard does the person have to push if the crate weights 400 n

a) 4.5

The mechanical advantage of a frictionless ramp is given by:

where

L is the length of the ramp

h is the height of the ramp

In this problem,

L = 18 m

h = 4 m

Substituting these values into the formula, we find

b) 88.9 N

For a frictionless ramp, the input work is equal to the output work:

where

is the force applied by the person

L = 18 m is the length of the ramp

is the output force, which corresponds to the weight of the crate

h = 4 m is the height of the ramp

Solving the equation for ,

in simple terms, the principle states that the buoyancy force on an object is equal to the weight of the fluid displaced by the object, or the density of the fluid multiplied by the submerged volume times the gravitational acceleration, g. this is also known as upthrust.

see earlier answer