Question

A plane is flying at a velocity of 120 m/s in the positive x direction. The plane is planning on dropping a ball in a net in the middle of a field. The plane is 100m off the ground. If the ball is dropped while moving at this rate,

a. How long will the ball be in the air

b. How far away from the net should he let the ball go

c. final velocity of ball in x direction

Answer 1

Let the horizontal distance between the point of drop and the net be 'R' metres and it takes 't' time to reach

the y component of initial velocity is zero {u_y=0; u=u_x=120 m/s}

given,

h=100 m ; u=120 m/s;

a) for vertical motion (accelerated)

h=u_yt +0.5gt²

100=0 + 0.5*9.8*t²

t = 4.517 seconds

b) for horizontal motion (unaccelerated)

R=t*u_x = 4.517*120 = 542.04 m

c) since the horizontal motion (in x direction) is unaccelerated hence, the final velocity in x direction remains unchanged.

v_x=u_x=120 m/s