Aseaplane flies horizontally over the ocean at 50 meters/second. it releases a buoy, which lands after 21 seconds. what's the vertical displacement from the plane to the ocean? (note: displacement will end up negative, since the direction is down.) part a: enter the variable symbol for the quantity you need to find. use your keyboard and the keypad to enter your answer. then click done.

The motion of the buoy consists of two independent motions on the horizontal and vertical axis.

On the horizontal axis, the motion of the buoy is a uniform motion with constant speed . On the vertical axis, the motion of the buoy is a uniformly accelerated motion with constant acceleration . The vertical position of the buoy at time t is given by

where h is the initial heigth of the buoy when it is released from the plane. At the time t=21 s, the buoy reaches the ground, so y(21 s)=0. If we substitute these two numbers inside the equation, we can find the value of h, the vertical displacement from the plane to the ocean: