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]
[g = 10ms2]
-
A.
100N -
B.
620N -
C.
50N -
D.
310N
Correct Answer: Option 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.