Asked by Millie

Jean dangles her watch from a thin piece of string while the jetliner she is in takes off. She notices that the string makes an angle of 22° with respect to the vertical while the aircraft accelerates for takeoff, which takes about 18 seconds. Estimate the takeoff speed of the aircraft.
Answered by bobpursley
tan22=ma/mg= a/g

a= g tan22

You know acceleration.

vf= at you know a, time t.
Answered by Millie
I keep getting Vf= 1.56 m/s which webassign says is wrong. It's in the chapter about Newtons laws of motion so, even though it is not included in the question, could that have a bearing on my answer, and if so how?
Answered by bobpursley
It would help if you put your calculator in degrees, and worked with 22 degrees, not 22 radians. Goodness.
Answered by Millie
oh, thank you. I forgot to do that after my calc homework