4 secondsIt will take 4 seconds to fall 78.4 meters
Use the equation y = 0.5 g t2 and substitute -9.8 m/s/s for g. The vertical displacement must then be subtracted from the initial height of 78. 4 m.
At t = 1 s, y = 4.9 m (down) so height is 73.5 m (78.4 m - 4.9 m )
At t = 2 s, y = 19.6 m (down) so height is 58.8 m (78.4 m - 19.6 m )
At t = 3 s, y = 44.1 m (down) so height is 34.3 m (78.4 ...
4 secondsIt will still take 4 seconds to fall 78.4 meters
Use the equation y = 0.5 g t2 and substitute -9.8 m/s/s for g. The vertical displacement must then be subtracted from the initial height of 78. 4 m.
At t = 1 s, y = 4.9 m (down) so height is 73.5 m (78.4 m - 4.9 m )
At t = 2 s, y = 19.6 m (down) so height is 58.8 m (78.4 m - 19.6 m )
At t = 3 s, y = 44.1 m (down) so height is 34.3 m ...
Technically no, the work done is not increasing the potential energy, it is decreasing it! We haven t converted energy into a form that we can tap into again.