Start Free Mock LoginAlready registered? Login here

Physics - Kinematics Question with Solution | TestHub

PhysicsKinematics1-DHard2 minQB

PhysicsHardsingle choice

Having gone through a plank of thickness h , a bullet changed its velocity from $v_{0}$ to v . Find the time of motion of the bullet in the plank, assuming the resistance force to be proportional to the square of the velocity.

Options:

Answer:

Solution:

$F = k v^{2}$

$- n \frac{v d v}{d s} = k v^{2}$

$\frac{d v}{v} = \frac{- k}{m} d s$

$ln (\frac{v _{0}}{v}) = \frac{kh}{m}$

$- m \frac{d v}{d t} \frac{- 1}{v ^{2}} d v (\frac{1}{v} - \frac{1}{v _{0}}) = k v^{2} = \frac{k}{m} d t = \frac{k t}{m}$

$t = \frac{m}{k} (\frac{v _{0} - v}{v v _{0}}) = \frac{h}{ln ( \frac{v _{0}}{v} )} (\frac{v _{0} - v}{v v _{0}})$

Stream:JEESubject:PhysicsTopic:KinematicsSubtopic:1-D

⏱ 2mℹ️ Source: QB

Doubts & Discussion

Loading discussions...