General Launch Angle problem

ilovephysics · Oct 14th 2016, 07:35 PM

A football quarterback shows off his skill by throwing a pass 45.10 m downfield and into a bucket. The quarterback consistently launches the ball at 39.00 ∘ above horizontal, and the bucket is placed at the same level from which the ball is thrown.

What initial speed is needed so that the ball lands in the bucket?
R = initial velocity ^2 / gravity * sin2theta, which gives initial velocity needed as 21.3 m/s.

By how much would the launch speed have to be increased if the bucket is moved to 48.40 m downfield?

I plugged in 48.4 and solved for initial velocity again and came up with 22 m/s but that isn't correct. I also thought maybe it wanted the difference (22-21.3) but that wasn't right either. Is initial launch speed different than initial velocity?

skeeter · Oct 14th 2016, 08:08 PM

Without rounding until finished, I get a difference of 0.763962 m/s

Try 0.8 m/s ?

a football quarterback shows off his skill by throwing a pass 44.40 m downfield and into a bucket. the quarterback consistently launches the ball at 39.00 ∘ above horizontal, and the bucket is placed at the same level from which the ball is thrown.