A ball is dropped out of a window and hits the ground at 14.5 m/s. How long did it take to fall to the ground?
1 answer:
Answer:
Explanation:
Use the one-dimensional equation:
which says that the final velocity of a falling object is equal to its initial velocity times the acceleration of gravity times the time it takes to fall. We have the final velocity, -14.5 (negative because its direction is down and down is negative), initial velocity is 0 (because it was held still by someone before it was dropped), and acceleration is -9.8 (negative again, because direction is down while acceleration increases). Filling in:
-14.5 = 0 - 9.8t and
-14.5 = -9.8t so
t = 1.5 seconds
You might be interested in
Answer:
a) , b)
Explanation:
a) The maximum height is obtained with the help of the First and Second Derivative Tests:
First Derivative
Second Derivative
(absolute maximum)
The maximum height reached by the ball is:
b) The time required by the ball to hit the ground is:
Just one root offers a solution that is physically reasonable:
The velocity of the ball when it hits the ground is: