Question
After the engine of a moving motorboat is cut off, the motorboat retards with retardation directly proportional to v. What is the magnitude of velocity at any instant after the engine is cut off, if the velocity at the time of cut off is v0?
Solution
Given,
Retardation of the boat,
Therefore,
r = kv; k is the proportionality constant.
Now, we know that acceleration is given by rate of change of velocity.