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?

5.5 N

We are given;

We need to calculate the apparent weight when in liquid .

Upthrust = Real weight - Apparent weight

              = 10 N - 7 N

               = 3 N

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

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

it is easily magnetized.