Question

A block of wood measuring $5\text{m}$ long, $4\text{m}$ wide and $0.5\text{m}$ thick is placed on a table such that its face with the maximum area is in contact with the table surface. Find the pressure exerted on the table due to the block if the mass of the block is $4000\text{kg}$.

• A. $20\text{Pa}$
• B. $2000\text{Pa}$
• C. $200\text{Pa}$
• D. $4000\text{Pa}$

Answer 1

The correct option is B $2000\text{Pa}$

The force exerted by the block on the table is the weight of the block of wood, which is:
$F=mg=4000\times 10=40000\text{N}$.
The area in contact according to the question: $A=5\times 4=20{\text{m}}^2$
Therefore, pressure exerted by block is given as:
$P=\frac{F}{A}=\frac{40000}{20}=2000{\text{N/m}}^2=2000\text{Pa}$