Question

A force of 15 N is required to lift an object that is underwater. The object displaces 2 L of water (1 L of water weighs 10 N). What is the weight of the object out of water?

• A. $15N$
• B. $25N$
• C. $35N$
• D. $45N$

Answer 1

The correct option is C $35N$

Given: The force required to lift underwater is $15N$.

The amount of water displaced IS $2L$.

The force required to lift the object in water = Weight of object out of water -buoyant force

The buoyant force acts on the body due to the amount of liquid displaced. So, the buoyant force on an object will be:

$F_b=2\times 10=20N$

Now,

$\Rightarrow 15N=$ Weight of object out of water $-20N$

$\therefore$ Weight of object out of water $=20N+15N=35N$

Option $C$ is correct.