Question

A rectangular block having a weight of 500N has the following dimensions 100cm x 50cm x 10cm. If the block is kept on a horizontal table,
(a)Calculate the maximum pressure that it can exert on the table.(b)Calculate the minimum pressure that it can exert on the table.

Answer 1

Answer:

Weight,W = 500N

In this case the weight is equal to force acting on the top of the table in the downward direction.

which means,

Weight = Force,F

OR

F=500N

Now, here comes a twist.

see We know the formula of pressure,

P = Force/area.

Now it can be seen that pressure is inversely proportional to area, which means if area is small than pressure will be huge and if the area is large than pressure will be small.

here we go:

So for part(I)

Maximum pressure is supposed to be calculated which means that we need small surface area of that rectangular box in contact with the table.

So dimensions which will give a small surface surface Area=area of a rec.. side=b×h

-50 × 10

-500cm

=5m

Now P=F/A

P=500/5

Maximum pressure=100pascal/pa

for part (ii)

minimum pressure this means we need large surface area-

dimensions which will give large surface area

surface Area=area of a rec.. side=L×B

100×50

5000cm

50m

Now,P=F/A

P=500/50

P=10pascal/pa

Minimum pressure=10pascal/pa