Question

A body has a weight 120 N in air and displaces a liquid of weight 30 N when immersed in the liquid. If so the weight in the liquid is:

• A. 150 N
• B. 90 N
• C. 60 N
• D. 30 N

Answer 1

Answer:

B. 90 N

To find the weight of the body in the liquid, we need to consider the buoyant force exerted by the liquid.

Step 1: Understand the concept of buoyancy

When a body is immersed in a liquid, it experiences an upward buoyant force equal to the weight of the liquid displaced.

Step 2: Calculate the buoyant force

The weight of the liquid displaced is 30 N, which is equal to the buoyant force.

Step 3: Calculate the weight in the liquid

The weight of the body in the liquid is its weight in air minus the buoyant force.
Weight in liquid = Weight in air - Buoyant force
Weight in liquid = 120 N - 30 N
Weight in liquid = 90 N

The final answer is: 90​