带空气阻力的自由落体问题A potato of mass 0.5 kg moves under Earth’s grav

带空气阻力的自由落体问题
A potato of mass 0.5 kg moves under Earth’s gravity with an air resistive force of –kmv.
(a) Find the terminal velocity if the potato is released from rest and k = 0.01 s–1.
(b) Find the maximum height of the potato if it has the same value of k,but is initially shot directly upward with a student-made potato gun with an initial velocity of 120m/s.