1. An airline passenger dangles her watch from a string while the jet takes off. The string makes an
angle of 25 o with respect to the vertical (i.e. 65 o from the horizontal) while the aircraft speeds up from
rest for takeoff, which takes about 18 seconds. The watch has a mass of 0.15 kg.
(a) On the dot below that represents the watch, draw and label the forces (not components)
that act on the watch. Assume the airplane is moving to the right.

(b) Is the acceleration of the airplane greater than, less than, or equal to the acceleration of the watch?
 Greater than
 Less than
 Equal to
Justification:

(c) Is the net force experienced by the airplane greater than, less than, or equal to the net force
experienced by the watch?
 Greater than
 Less than
 Equal to
Justification:

(d) Calculate the takeoff speed of the aircraft.

(e) Calculate the distance the airplane traveled along the runway before takeoff.

(f) Justify the reasonability of the answer to (e) by comparing it to the lengths of actual runways.