Y(initial) = 9
V(initial) = 168
V(final) = 0
g(accel-grav) = 32 (in feet per second
squared)
Use the following equation:
V(final) = V(initial) + a(t)
Since this object is moving straight up and
down, a = -32
Enter the knowns into the equation
0 = 168 - 32t
32t = 168
t = 168/9.8
t = 5.25
Now that you know the time it takes to
reach it's maximum, use the general
kinematics equation to solve for final
distance:
y(final) = y(initial) + V(initial)(t) + (1/2)a
(t²)
y(final) = 9 + 168(5.25) + (1/2)(-32)
(5.25²)
= 9 + 882 - 441
= 450 feet
M<KPN = 1/2(90+50) = 140/2=70
answer D. 70 (last choice)
Chebyshev came up with the
limits on how much or how many of the data must lie close to the mean. In specific
for any positive k, the proportion of the data that lies within k standard
deviations of the mean is at least: <span>
1 - 1/k²
<span>In this problem the
mean is 47 yrs therefore:
(47 – 17.3) = 29.7 = (76.7 - 47) </span></span>
The value of k is
calculated using the formula:<span>
29.7 / 11 = 2.7 = k</span>
So the % of gym members
aged between 19.4 and 76.6 is: <span>
1 - 1 / (2.6)² = 0.863 = 86.3 %</span>
<span>Therefore 86.3% of the
gym members are aged between 19.4 and 76.6</span>
