The velocity of a small ball of mass 0.3 g and density 8 g/cc when dropped in a container filled with glycerine becomes constant after some time. If the density of glycerine is 1.3 g/cc, then the value of viscous force acting on the ball will be x × 10–4 N. The value of x is _______. [use g = 10 m/s2]
Correct Answer: 25
Solution and Explanation
Fv=6πηrvT
Fv+Fv=mg
⇒Fv=mg–FB
=10×(8–1.3)×\(\frac{0.3}{8}×10^{−3}\)
\(=2.5125×10^{–3} N\)
\(≃25×10^{−4} N\)
So, the answer is 25.
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Concepts Used:
Speed and Velocity
The rate at which an object covers a certain distance is commonly known as speed.
The rate at which an object changes position in a certain direction is called velocity.
Difference Between Speed and Velocity:
Read More: Difference Between Speed and Velocity