Question

Throwing a Wrench. An angry construction worker throws his wrench downward from a height of 128 feet with an initial velocity of 32 feet per second. The height of the wrench above the ground after t seconds is given by S(t)=-16t^2-32t+128.
a) What is the height of the wrench after 1 second?
b) How long does it take for the wrench to reach the ground?

Answer 1

Did I miss the question?

Answer 2

no it looks like i didn't add what is is i need help with here is what I am looking for from the above question
a)What is the height of the wrench after 1 sec
b)how long will it take the wrench to reach the ground

Answer 3

this is what I came up with for a) but I am unsure about it and I am not sure how to do b)
S(t)=-16t2-32t+128
S(1)=-16-32+128
S=-48+128
S=80

Answer 4

yes, on a.
Now on b, set s to zero, then solve for t. Notice it is a quadratic.

Answer 5

This what I go and now I am stuck. Can you please let me know what I need to do next or where I am going wrong

0=-16t2-32t+128
0=t2+2t+8

Answer 6

-16t^2 - 32t + 128
-16(t^2 + 2t - 8)
What multiplies to -8 and adds to 2
4 & -2
t^2 + 4t - 2t - 8
Group and remove commonalities
(t^2 + 4t) (-2t - 8)
t(t+4) -2(t+4)
(t+4)(t-2)
Solve each set for 0
t+4=0
t= -4

t-2=0
t=2