Question

49. A metallic sphere is made of an alloy of two metals 'p
and Q having specific gravities (or relative densities)
20 and 2, respectively. The sphere weighs 120 gwt in
air and 90 gwt in water. Find the percentage of the
mass of metal 'P' in the alloy.​

Answer 1

Answer:Let volume of sphere be V

let volume of P be x% of V and volume of Q will be (100-x)% of V

So, mass of P =( xV/100) * 20000

= 200xV

(using formula Density = mass/volume)

Mass of Q =( (100-x)V/100) * 2000

= 2000V -20xV

So, mass of P + mass of Q = total mass

200xV + 2000V-20xV = 0.12 (in kg)

180xV + 2000V = 0.12...(i)

As the sphere weights 90gwt in water

So, weight of liquid displaced= Vdg = (120-90) gwt

So, Vd = 0.03

V= 0.03/1000 m^3

Putting this value in equation (i)

180x*0.03/1000 + 2000*0.03/1000 = 0.12

5.4x +60 = 120

x = 11.11

So mass of P = 200xV = 66.66g

Explanation:

Answer 2

Answer:

55.56%

Refer the attached images for step-by-step explanation (from left to right)