A table, with four legs, weighs 5 N. The area of contact of one of its leg with the ground is 2.5 x 10-3 m². A man, with a mass of 9 kg, sits on the centre of the tabletop. What is the total pressure exerted on the ground by the table with the man on it?

Total force on 4 legs

=5 N + 9*9.8 N
= 93.2 N

Area of contact of each leg
= 2.5*10-3

Pressure on each leg
= 93.2/(4*2.5*10-3
= 9320 N/m²
= 9320 Pa (pascals)

To find the total pressure exerted on the ground by the table with the man on it, we need to consider the weight of the table and the man, as well as the area of contact between the table leg and the ground.

Let's break down the problem step by step:

1. Calculate the weight of the table:
The weight of the table is given as 5 N. Weight is a force, which can be calculated using the formula: Weight = mass x acceleration due to gravity. In this case, the mass is not given, so we need to use the formula in reverse: mass = Weight / acceleration due to gravity. Given that acceleration due to gravity is approximately 9.8 m/s², we can calculate the mass of the table using the weight provided.

Weight = mass x acceleration due to gravity
5 N = mass x 9.8 m/s²
mass = 5 N / 9.8 m/s²

2. Calculate the weight of the man:
The weight of the man can be calculated in the same way as we did for the table. The mass of the man is given as 9 kg.

Weight = mass x acceleration due to gravity
Weight of the man = 9 kg x 9.8 m/s²

3. Calculate the total weight:
To find the total weight, we need to sum up the weights of the table and the man.

Total weight = Weight of the table + Weight of the man

4. Calculate the pressure:
Pressure is defined as force per unit area. In this case, the force is the total weight, and the area is given as the contact area of one table leg with the ground, which is 2.5 x 10^-3 m².

Pressure = Total weight / Area

Now you can substitute the values into the formula to find the total pressure exerted on the ground by the table with the man on it.