Physics Help ASAP?

Question

A boat of mass 250 kg is coasting, with its engine in neutral, through the water at speed 3.00 m/s when it starts to rain. The rain is falling vertically, and it accumulates in the boat at the rate of 10.0 kg/hr.

The drag is proportional to the square of the speed of the boat, in the form F_d= 0.5 v^2. What is the acceleration of the boat just after the rain starts? Take the positive x axis along the direction of motion.
Express your answer in meters per second per second.

Answer 1

Acceleration a = F/m Since F is a drag force, the acceleration is negative

a = -0.5*v^2 / (250 + 10*t) just as the rain starts, t = 0; the acceleration at t = 0 is

a = -0.5*3.00^2/250 = -0.018 m/sec^2