An object weighs 7.84 N when it is in air and 6.86 N when it is immersed in water of density 1000 kg/m3. What is the density of the object?

8000 kg/m^3

Explanation:

Weight in air = 7.84 n

Weight in water = 6.86 N

density of water = 1000 kg/m^3

Let d be the density of object

According to the Archimedes principle, when a body is immersed in a liquid partly or wholly, it experiences an upward force which is called buoyant force. The buoyant force is equal to the loss in weight of the body.

Loss in weight of the object = Weight of object in air - weight of object in water

Loss in weight = 7.84 - 6.86 = 0.98 N

Volume of body x density of water x g = 0.98

Let V be the volume of body

V x 1000 x 9.8 = 0.98

V = 10^-4 m^3

Weight in air = Volume of body x density of body x g

7.84 = 10^-4 x d x 9.8

d = 8000 kg/m^3

Thus, the density of body is 8000 kg/m^3.