Imagine that a tank is filled with water. The height of the liquid column is 7 meters, and the area is 1.5 square meters [tex] \left( m^2 \right) [/tex]. What is the force of gravity acting on the column of water?

A) [tex] 68,600 \, N [/tex]
B) [tex] 102,900 \, N [/tex]
C) [tex] 73,500 \, N [/tex]
D) [tex] 110,700 \, N [/tex]



Answer :

To find the force of gravity acting on the column of water in the tank, we'll go through a detailed step-by-step process.

1. Calculate the Volume of the Water Column:
The volume of the water column can be found using the formula:
[tex]\[ \text{Volume} = \text{Height} \times \text{Area} \][/tex]
Given:
- Height = 7 meters
- Area = 1.5 square meters

Substituting the values:
[tex]\[ \text{Volume} = 7 \text{ meters} \times 1.5 \text{ square meters} = 10.5 \text{ cubic meters} \][/tex]

2. Calculate the Mass of the Water:
To find the mass of the water, we need the density of water, which is 1000 kg/m³. The mass can be calculated using the formula:
[tex]\[ \text{Mass} = \text{Volume} \times \text{Density} \][/tex]
Given:
- Volume = 10.5 cubic meters
- Density of water = 1000 kg/m³

Substituting the values:
[tex]\[ \text{Mass} = 10.5 \text{ cubic meters} \times 1000 \text{ kg/m}^3 = 10500 \text{ kg} \][/tex]

3. Calculate the Force of Gravity:
The force of gravity can be calculated using Newton's second law of motion (Force = Mass × Acceleration). Here, the acceleration due to gravity (g) is 9.81 m/s². The formula for the force of gravity is:
[tex]\[ \text{Force\_gravity} = \text{Mass} \times \text{Gravity} \][/tex]
Given:
- Mass = 10500 kg
- Gravity = 9.81 m/s²

Substituting the values:
[tex]\[ \text{Force\_gravity} = 10500 \text{ kg} \times 9.81 \text{ m/s}^2 = 103005 \text{ N} \][/tex]

Thus, the force of gravity acting on the column of water is [tex]\( 103005 \text{ N} \)[/tex].

Reviewing the given options:
A) 68,600 N
B) 102,900 N
C) 73,500 N
D) 110,700 N

It is clear that none is exactly [tex]\( 103005 \text{ N} \)[/tex], but the closest is option B) [tex]\( 102,900 \text{ N} \)[/tex].

Therefore, the answer is:
B) [tex]\( 102,900 \text{ N} \)[/tex]