A body of mass 36kg falls through a viscous liquid which offers a drag force of 260N on the body. The upthrust on the body at terminal velocity is? [g = 10ms2]
A. 100N B. 620N C. 50N D. 310N
Correct Answer: A
Explanation
For anybody falling through a viscous liquid, at its terminal velocity. the resultant force acting on its is zero. from the equation: Mg - v - u = 0. where v = viscous drag U = upthrust Mg = weight of the body. ∴ 36 x 10 - 260 - U = 0 ∴ U = 360 - 260 = 100N Upthrust on the body = 100N.
