[uzair]

A metalic block produces a tension of 10 N when suspended with a string without immersing it in to the water, and when immersed in the water tension was reduced to 8N find the density of metalic block?

[Borek]

Read the forum rules.

[uzair]

Plz Boorek don't try to fool me I'm sure, I'm not gona get its solution from the forum rules. :fishing:

[green-goblin]

Plz Boorek don't try to fool me I'm sure, I'm not gona get its solution from the forum rules. :fishing:

LOL   are i'm not sure if your being series with that reply or not

[Hunt]

This seems like Fluid statics to me.

From Netwon's 2nd law, sum of forces = 0 at Eq
This means Tension = Weight of the mb ( before inserting it in water )

This implies Wt of the mb = 10 N

When inserted in water, I'll assume that the metallic block reaches equilibrium without reaching the buttom surface.

At Eq : T_mb + F_b = Wt_mb

The force exerted by water is the Bouyant Force F_b.
 
F_b = 10N - 8N = 2N

F_b = V_immersed x g x d_water

2 N =  V_immersed x 9.8N/Kg x 1Kg/L

V_immersed = 0.2 L

Since the mettalic block is totally immersed, we can conclude V_immersed = V_total , that is the total volume of the metallic block.

Wt_mb = d_mb x g x V_T

10 N = d_mb x 9.8 N/Kg x 0.2 L

d_mb = 5.1 Kg/L