Question: A stone is thrown verticall upward with a speed of 18.0 m/s. (a) How fast is it moving when it reaches a height of 11.0m? (b) How long is required to reach this height?(adsbygoogle = window.adsbygoogle || []).push({});

a. Work

v(i)=18.0 m/s

x=11.0 m

x(i)=0

g=9.8 m/s ^2

v=?

v^2=v(i)^2-2g(x-x(i))

v^2=18^2-2(9.8)(11-0)

v^2=324-215.6

Answer: v=10.41 m/s

b. Work

v=10.41 m/s

V(i)=18

g= 9.8 m/s^2

v=v(i)-gt

10.41=18-9.8t

-7.56=-9.8t

Answer: t=.77 seconds

Did I do these problems correctly?

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# Homework Help: Stones and velocity

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