Flying Circus of Physics Catapulting mushrooms. Certain mushrooms launch their s
ID: 2045850 • Letter: F
Question
Flying Circus of Physics
Catapulting mushrooms. Certain mushrooms launch their spores by a catapult mechanism. As water condenses from the air onto a spore that is attached to the mushroom, a drop grows on one side of the spore and a film grows on the other side. The spore is bent over by the drop's weight, but when the film reaches the drop, the drop's water suddenly spreads into the film and the spore springs upward so rapidly that it is slung off into the air. Typically, the spore reaches a speed of 1.70 m/s in a 5.10 µm launch; its speed is then reduced to zero in 1.30 mm by the air. Using that data and assuming constant accelerations, find the acceleration in terms of g during (a) the launch and (b) the speed reduction
Explanation / Answer
Use your handy equation of motion: vf^2 - vi^2 = 2 a distance So to accelerate from rest: a = vf^2 / (2 distance) And to decelerate, use that same formula and the same speed with the deceleration distance. Don't worry about signs for this since they just want magnitudes. They ask you to express your answer in terms of g, so divide by g and that will give you the number of g's. Be careful to handle the millimeters and micrometers correctly.