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
Standard notation simply means the normal way or writing numbers.
10^-3= 1/10^3
1/10^3=1/1000
1/1000=0.001
Final answer: 0.001
Area=(base x height)/2
base=5.8 cm
height=2.4 cm
Area=(5.8 cm * 2.4 cm) / 2=6.96 cm²
The answer is A 6.96
(y-x) (2+3)= (yx)(5)
But am not sure it could be =(2-3) (y+x) = (1) (yx)
