A rescue helicopter is hovering over a person whose boat has sunk. One of the rescuers throws a life preserver straight down to the victim with an initial velocity of 1.40 m/s and observes that it takes 1.8 s to reach the water. (a) List the knowns in this problem. (b) How high above the water was the preserver released? Note that the downdraft of the helicopter reduces the effects of air resistance on the falling life preserver, so that an acceleration equal to that of gravity is reasonable.

Step-by-step solution 44PE Step 1 of 3 The formula for the final po sition y of an accelerating body is, Here, y o is the initial position, u is the initia l velocity, t is the time interval and a is the acceleration of the body. Step 2 of 3 (a) The quantities which are known are, Initial velocity u with which rescuer throws the life preserver to the victim is 1.40 m/s, Time t for reaching the life preserver to the victim is 1.8 s, The acceleration of the life preserver is an d the initial position y o of the life preserver is 0 m.