Answer:
son 60 puntos ...!!!!!!!!
We are given a watermelon dropped at free fall from a building 320 meters above the sidewalk. Superman is headed down at 30 meters per second. We are asked to determine how fast is the watermelon going when it passes Superman. To solve for the final velocity of the watermelon, we will use one of the kinematic equations (free fall):
vf = vi + a*t
where vf is the final velocity
vi is the initial velocity, zero
a is the acceleration, in this case, gravitational acceleration = 9.8m/s^2
t is time
we also need to set-up another equation using the distance:
d = vf + vi / 2 * t
(1) 320 m = vf * t /2
(2) vf = 9.8 m/s^2 * t
From here, we have two equations and two unknown, thus we can solve the problem by substitution.
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Answer:
The total number of U.S. high school students that played on a sports team that year can be estimated to be 7,950,000.
Step-by-step explanation:
From the random sample, we can expect that 
of all students played on a sports team that year. So in the bigger sample of 15900000 high school students, we can expect 
students to have played on a sports team that year.
Answer:
1. $109.20 2. $46.80
Step-by-step explanation:
Doing the math, we find that 30% of 156 (138+18) is 46.80, which answers the second part of this problem. Plugging this value into the first part of the equation gives us what Stefan originally paid.
Good luck! Hope this helps!
