Word Problem Exercises: Vertical Motion
By C Adams
Directions and/or Common Information:
The formula to model the height of an object t seconds after it has been dropped is
- h = -16t2 + h0 (in feet) or
- h = -4.9t2 + h0 in (meters)
If an object has been thrown or launched, the formula to model the height of the object t seconds after it has been launched is
- h = -16t2 + vot + h0 (in feet) or
- h = -4.9t2 +vot + h0 (in meters)
In all of these equations:
h = the height of the object at any given point in time
t = time the object is in motion (in seconds)
h0 = the initial height (in feet or meters) from which the ball was dropped or launched
v0 = the initial velocity (in ft/sec or m/sec) of the object when it was launched.
If v0 < 0, the object was propelled downward
v0 = 0, the ball was dropped from rest with no initial velocity
v0 > 0, the ball was propelled upward.
If a rock is dropped off of a bridge that is 30 feet above a river, how long will it take the rock to hit the water?
A tennis player hits a ball 1 meter above the ground with a velocity of 20 m/sec. When will the ball be at a height of 1 meter again?
A tennis player hits a ball 1 meter above the ground with a velocity of 20 m/sec. What is the maximum height the ball will reach?
A tennis player hits a ball 1 meter above the ground with a velocity of 20 m/sec. How long will it take the ball to hit the ground?
A hawk, flying at a height of 50 feet, spots a rat on the ground. If he dives down to catch the rat at a speed of 45 feet per second, how long will it take him to catch the rat?