An object weighs 10.0 N in air and 7.0 N in water. What is its weight when immersed in a liquid of relative density 1.5?

A. 4.50N
B. 4.67N
C. 5.50N
D. 6.67N
E. 8.50N

Correct Answer:

Option C – 5.50N

Explanation:

Upthrust in water Uw = 10-7 = 3N

Uw=pvg; 3=1000×v×10

V=3×10−³m³

UL is upthrust in liquid=1500×3×10−³×10 = 4.5N

UL=Wa-WL

WL = 10-4.5

=5.5N