(a) If a balloon filled with air and its mouth untied/ is released with its mouth in the downward direction, it moves upwards. Why?
(b) An unloaded truck weighing 2000 kg has a maximum acceleration of 0.5 m/s2. What is the maximum acceleration when it is carrying a load of 2000 kg?
(a) If of a balloon filled with compressed air and its mouth untied is released with its mouth in the downward direction, the balloon moves in the upward direction because the air present in the balloon rushes out in the downward direction. The equal and opposite reaction of downward going air pushes the balloon upwards.
(b) Mass of the unloaded truck, m1 = 2000 kg
Acceleration a1 = 0.5 m/s2
Mass of loaded truck, m2 = 2000 + 2000
= 4000 kg
Acceleration a2
m1 x a1 = m2 x a2
a2 = \(\frac{2000 \times 0.5}{4000}\)
= 0.25 m/s2