Question

If a baseball player hits a baseball from 4 feet off the ground with an initial velocity of 64 feet per second, how long will it take the baseball to hit the ground? Use the equation h = −16t2 + 4t + 4. Round your answer to the nearest hundredth.
please answer asap

Answer 1

Answer:

t = 4.06 sec

Step-by-step explanation:

First of all, if the initial velocity is 64 feet per second, then the parabola should actually look like this:

$h(t)=-16t^2+64t+4$

The initial velocity is in the place of our linear term, so it should be 64 not just 4.

Anyways, the h(t) value represents the height of the object after a certain number of seconds, t, it was launched from the initial height. We are looking for the length of time it takes the object to hit the ground.  The height of something on the ground is 0.  So we replace h(t) with a 0 and factor to solve for the values of t:

$0=-16t^2+64t+4$

If you plug that into the quadratic formula to factor it, you will get that the values of t are

t = -.06 seconds and

t = 4.06 seconds

We all know that the 2 things in math that will never EVER be negative are time and distance/measures, so we can safely disregard the negative value of time.  

It takes the ball 4.06 seconds to hit the ground when it is launched from an initial height of 4 feet.