Need help with this question!!!

The rate of change of the velocity of a bullet fired into a sand pile is directly proportional to the square root of the velocity of the bullet. 1|I'llrite and solve a differential equation that expresses the rate of change of the bullet's velocity. If a bullet with initial velocity of 239 feet per second {1'sz will travel for {1.035 seconds after impact. then for how long will a bullet with initial velocity of l-[l fps travel? Give your answer to 3 decimal places. travel time = :l seconds