17.2k views
5 votes
An object weighs 10N in air and 70N in water .What is it's weight when immersed in a liquid of relative density 1.5?​

User Wouzz
by
5.7k points

1 Answer

3 votes

Answer:

5.5 N

Step-by-step explanation:

We are given;

  • Real weight of an object in air as 10 N
  • Apparent weight in water as 7 N
  • Relative density of a liquid is 1.5

We need to calculate the apparent weight when in liquid .

  • First we calculate upthrust

Upthrust = Real weight - Apparent weight

= 10 N - 7 N

= 3 N

  • Then calculate the upthrust in the liquid.

we need to know that;

Relative density of a liquid = Upthrust in liquid/Upthrust in water

Therefore;

1.5 = U ÷ 3 N

Upthrust in liquid = 3 N × 1.5

= 4.5 N

  • Therefore, the upthrust of the object in the liquid is 4.5 N

But, Upthrust = Real weight - Apparent weight

Therefore;

Apparent weight in Liquid = Real weight - Upthrust

= 10 N - 4.5 N

= 5.5 N

Thus, the weight when the object is immersed in the liquid is 5.5 N

User Jabuj
by
6.3k points