Aset of bookshelves rests on a hard floor surface on four legs, each having a cross-sectional dimension of 3.0×4.1cm in contact with the floor. the total mass of the shelves plus the books stacked on them is 262 kg. calculate the pressure in pascals exerted by the shelf footings on the surface.

Step-by-step explanation:

The pressure exerted by an object is given by:

where

F is the magnitude of the force

A is the area of the surface perpendicular to the force

In this problem, the force is the weight of the books + the shelf, which is given by

where

m = 262 kg is the total mass

is the acceleration of gravity

Substituting,

The area of the four legs is:

Therefore, the pressure exerted on them is:

answer:  

step-by-step explanation:

here x represents the height of the pole,

and, the height of the shadow of the pole is 12 feet.

also, the angle of elevation from the top of the pole is 40°,

therefore,

by the low of sine,

which is the required equation for finding the value of x,