( )A cannonball is fired horizontally from the top of a cliff. The cannon is at height H = 80.0m above ground level, and the ball is fired with initial horizontal speed v0. Assume acceleration due to gravity to be g = 9.80m/s2 .
The time it takes a cannonball fired horizontally from a 100m high
cliff to reach the ground is just
H = * t + 1/2 * g * tg^2; (Vyo = 0 for a horizontal shot, solve for tg)
tg^2 = 2 * H / g = 200 / 9.8
tg = 4.5 sec
After half of this time (tg/2 = 2.26 sec), the cannon ball has dropped:
Y = Vyo * t + 1/2 * g * (2.26)^2
Y = 1/2 * 9.8 * (2.26)^2
Y = 25 m (from the top of the cliff)
Notice that the given horizontal initial velocity Vo is irrelevant to the problem.
Get Answers For Free
Most questions answered within 1 hours.