A ball is thrown upward with an initial velocity V 0 from the surface of the earth. The motion of the ball…

A ball is thrown upward with an initial velocity V0 from the surface of the earth. The motion of the ball is affected by a drag force equal to  mγv2 (where m is mass of the ball, v is its instantaneous velocity and γ is a constant). Time taken by the ball to rise to its zenith is:
  1. 1γgln1+γgV0
  2. 1γgtan-1γgV0
  3. 1γgsin-1γgV0
  4. 12γgtan-12γgV0

Solution

Net force on ball,
F=-mg-mγv2
a=-g-γv2
dvdt=-g-γv2
v=V0v=0dvg+γv2=t=0t-dt
1gγtan-1γgvv=V0v=0=-t
t=1γgtan-1 γgV0

Asked in: JEE Main 2019 (10 Apr Shift 1)

Practice more Laws of Motion questions on Aicharya