A stone, of mass m , falls vertically downwards under gravity through still water. The initial speed of the stone is u . Find an expression for v at time t .
- Ma = mg - Lmv 2) dv/dt = g-Lv 3)-1/L *(ln(g -Lv)/(g - Lu)) = t 4) g - Lv/ g - Lu = e-Lt 5) Rearrange to.... v = 1/L *(g-(g - Lu) e-Lt) Missed some steps as it was relatively long, can perform this fully in person during the interview if preferred.
JW
