Answer:
This is hard to read, but i guess that the equation is:
So we have some things to solve:
First, for any number:
x^0 = 1
then 5^0 = 1.
And for negative powers,
x^-n = (1/x)^n.
And we
Then we can rewrite our equation as:
now we can cancel the seven in the numerator and the denominator
now, remember the relation:
a^x*a^y = a^(x+y)
then:
2*2^3 = 2^4
and 2^4/2^9 = 2^-5 = (1^2)^5
Then our equation is:
15/2^5 = 0.46875
2+½, is just 2½, now divided by 1/4.
let's first convert the mixed fraction to improper, and then divide.
![\bf \stackrel{mixed}{2\frac{1}{2}}\implies \cfrac{2\cdot 2+1}{2}\implies \stackrel{improper}{\cfrac{5}{2}} \\\\[-0.35em] ~\dotfill\\\\ \cfrac{5}{2}\div \cfrac{1}{4}\implies \cfrac{5}{2}\cdot \cfrac{4}{1}\implies \cfrac{5}{1}\cdot \cfrac{4}{2}\implies 5\cdot 2\implies 10](https://tex.z-dn.net/?f=%5Cbf%20%5Cstackrel%7Bmixed%7D%7B2%5Cfrac%7B1%7D%7B2%7D%7D%5Cimplies%20%5Ccfrac%7B2%5Ccdot%202%2B1%7D%7B2%7D%5Cimplies%20%5Cstackrel%7Bimproper%7D%7B%5Ccfrac%7B5%7D%7B2%7D%7D%0A%5C%5C%5C%5C%5B-0.35em%5D%0A~%5Cdotfill%5C%5C%5C%5C%0A%5Ccfrac%7B5%7D%7B2%7D%5Cdiv%20%5Ccfrac%7B1%7D%7B4%7D%5Cimplies%20%5Ccfrac%7B5%7D%7B2%7D%5Ccdot%20%5Ccfrac%7B4%7D%7B1%7D%5Cimplies%20%5Ccfrac%7B5%7D%7B1%7D%5Ccdot%20%5Ccfrac%7B4%7D%7B2%7D%5Cimplies%205%5Ccdot%202%5Cimplies%2010)
Answer:
s = height above ground
s = 60 + 20 t - 4.9 t^2 (standard physics equation on earth)
at t = 0
s = 60 (clearly :)
now when does it hit the bleak earth?
That is when s = 0
4.9 t^2 - 20 t -60 = 0
solve quadratic and use the positive t (the negative t was back before you threw it if you had thrown it from the ground)
t = 6.09 or - 2.01
use t = 6.09
now to do the last part there are two obvious ways to get t at the peak
1. look for vertex of parabola
2. look for halfway between t = -2.01 and t = 6.09
I will do it the hard (11) waay by completing the square
4.9 t^2 - 20 t = -(s-60)
t^2 - 4.08 t = -.204 s + 12.2
t^2 - 4.08 t +2.04^2 = -.204 s +12.2 + 4.16
(t-2.04)^2 = -.204(s-80.2)
so
top at 80.2 meters at t = 2.04 s
===============
quick check on time
should be average of 6.09 and -2.01
=4.08 /2 = 2.04 check
