Question 17089: Suppose you throw a rock upward from a height of 64 feet with an intial velocity of 48 feet per second the rock will hit the ground after __ seconds.
Found 2 solutions by Earlsdon, tjnw79:
Answer by Earlsdon(6294)   (Show Source):
You can put this solution on YOUR website! The height, h, of an object thrown upward from an initial height, Ho, with an initial velocity, Vo, is given by the function h as a function of time, t:
Since Vo = 48 ft/sec and Ho 64 ft, then:
 You want to know at what time, t, will the rock hit the ground (h = 0). Set the above function = 0.
 Solve this quadratic equation for t. First, factor -16.
 Apply the zero products principle.
 Factor.
 Again, apply the zero products principle.
 and/or 
If t - 4 = 0, then t = 4 seconds
If t + 1 = 0, then t = -1 second...Discard this solution as negative time is not meaningful in this problem.
The rock hits the ground after 4 seconds.
Answer by tjnw79(57) (Show Source):
|
|
|
