A PIECE OF STONE WEIGHTS 180 N IN AIR AND 150 N IN A BEAKER CONTAINING 160 N OF METHYLATED SPIRIT. WHAT IS THE UP THRUST EXERTED ON THE STONE

• A. 50N
• B. 40N
• C. 30N ✓
• D. 20N
• E. 10N

The answer to the question is: C. 30N

The upthrust exerted on an object immersed in a fluid is equal to the weight of the fluid displaced by the object. In this case, the stone weighs 180 N in air and 150 N in a beaker containing 160 N of methylated spirit. To find the upthrust exerted on the stone, we can use Archimedes’ principle, which states that the buoyant force on an object is equal to the weight of the fluid displaced by the object.

First, we need to find the weight of the stone in the methylated spirit. The difference between its weight in air and its weight in the fluid gives us the buoyant force acting on it.

Weight of stone in air = 180 N

Weight of stone in methylated spirit = 150 N

Buoyant force = Weight of stone in air – Weight of stone in methylated spirit

Buoyant force = 180 N – 150 N

Buoyant force = 30 N

Therefore, the upthrust exerted on the stone is 30 N