7. You throw a baseball in the air with a starting velocity of 20 feet per second. The baseball is 5 feet high when it leaves your
hand. After how many seconds will it hit the ground?

You hit the ball when it  

falls back to a height of 4 ft. If you toss the ball with  

an initial velocity of 25ft/sec, how much time will pass  

before you hit the ball? Thanks!

Use the formula h = h0 + v0t - 16t2 since distance is given

in feet. (If distance were in meters, we would have to use

4.9 where the 16 is).

h0 represents the initial height. v0 represents the initial  

velocity, and h is height at the instant when t seconds have

elapsed.

>>...When tossing the ball into the air, your hand is 5 feet  

above the ground...<<So h0 = 5

>>...you toss the ball with an initial velocity of 25ft/sec...<<

So v0 = 25

So we substitute 5 for h0 and 25 for v0, making our formula

h = 5 + 25t - 16t2

>>...You hit the ball when it falls back to a height of 4 ft...<<

So we wish to find t (the number of seconds) has elapsed at the

instant when the ball is 4 feet high, so we substitute 4 for h

and solve for t:

4 = 5 + 25t - 16t2

16t2 - 25t - 1 = 0

Use quadratic formula, get solutions  

-.04 and 1.6.  We ignore the negative answer.  So the answer is

1.6 seconds approximately. Lol im nerdy

555.99.

step-by-step explanation:

hope this