Posted by Rachel on Wednesday, December 9, 2009 at 12:42am.
when apollo 15 astronaut David Scott dropped a hammer and a feather on the moon to demostrate that in a vacuum all bodies fall with the same (constant) acceleration, he droppes them from 4 feet above the lunar surface. the television shows them fallen more slowly than on earth, where ina vacum it would take only half a second for the fall of 4 feet. how long did it take the hammer and the feather to fall 4 feet ont he moon, if the moons gravitational acceleration is 13/80 that of earth?

Calc./ Physics  drwls, Wednesday, December 9, 2009 at 12:49am
H = (1/2) a t^2
t = sqrt(2H/a)
H is the height, which is kept constant. Since acceleration (a) is decreased by a factor 13/80, the time to fall is increased by a factor
sqrt(80/13) = 2.48
On the moon, the time to fall 4 ft is given by the equation
4 ft = (1/2)* (13/80)*32.2 ft/s^2 * t^2
t = 1.24 s