a girl dangles her watch from a thin piece of string while the jetliner she is in takes off. the string makes an angle of 29° with respect to the vertical while the aircraft accelerates for takeoff, which takes about 18 seconds. Estimate the takeoff speed of the aircraft.
i have some idea of how to begin it, but im kinda not sure! if you can help at all, it would be appreciated!
2006-11-02 14:12:31 · 2 answers · asked by tigerlilly 2 in Science & Mathematics ➔ Physics
There are 3 forces acting on the watch: its weight which is in the vertical direction and equal to mg, the centripetal force which is equal to ma, and the tension on the piece of string. If you draw the diagram showing these 3 forces, you will note that:
tan29=ma/mg
substitute known values:
0.554=a/9.8
a=0.554*9.8
=5.43m/s^2
Now solve for v using the formula:
v=u+at
Substitute known values:
v=0+5.43*18
=97.7m/s
2006-11-02 15:54:23 · answer #1 · answered by tul b 3 · 0⤊ 0⤋
The acceleration of the plane will equal the tangent of the 'dangle angle' times g. Having found the acceleration, the velocity after 18sec is just a*t
2006-11-02 14:17:46 · answer #2 · answered by Steve 7 · 0⤊ 0⤋