airplane problem?

Question

An airplane is flying with a velocity of 92.0 m/s at an angle of 21.0 degrees above the horizontal. When the plane is a distance 118 m directly above a dog that is standing on level ground, a suitcase drops out of the luggage compartment.

How far from the dog will the suitcase land? You can ignore air resistance.

Answer 1

Place the dog at y=0, x=0
and the airplane at y=118, x=0 when the suitcase drops

The equations of motion are
x(t)=92*cos(21)*t
y(t)=118+92*sin(21)*t-.5*g*t^2
when y(t)=0, the suitcase strikes the ground
solve for t at that moment (there will be two roots, use the positive root)
t=9.31 seconds

x(9.31)=800 m

j