A pendulum bob of mass 50 g hangs from the ceiling of an elevator. Determine the tension in the string given that the elevator is travelling upward with a deceleration of 1.2 m/s ^2 .

Step-by-step solution

Mass of the bob, m = 50 g = 0.05 kg The elevator is travelling upward with a deceleration of 1.2 m/s ^2 . This implies the acceleration of the elevator is directed downward, with magnitude a = 1.2 m/s ^2 . Writing the equation of motion for the bob: mg - T = ma T = m(g - a) Substituting g = 9.8 m/s ^2 and a = 1.2 m/s ^2 : T = 0.05(9.8 - 1.2) T = 0.05 8.6 T = 0.43 N