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Chemistry Forums for Students => Physical Chemistry Forum => Topic started by: uzair on March 24, 2006, 01:40:03 AM

Title: Numerical Problem relating to TENSION
Post by: uzair on March 24, 2006, 01:40:03 AM

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?

Title: Re:Numerical Problem relating to TENSION
Post by: Borek on March 24, 2006, 03:48:35 AM

Read the forum rules.

Title: Re:Numerical Problem relating to TENSION
Post by: uzair on March 24, 2006, 12:24:11 PM

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

Title: Re:Numerical Problem relating to TENSION
Post by: green-goblin on March 24, 2006, 02:30:51 PM

Quote from: uzair on March 24, 2006, 12:24:11 PM

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

LOL ;D   are i'm not sure if your being series with that reply or not :-\

Title: Re:Numerical Problem relating to TENSION
Post by: Hunt on March 25, 2006, 08:40:43 PM

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