A rock is thrown directly upward from the edge of the roof of a ...

[joe]

A rock is thrown directly upward from the edge of the roof of a building that is 66.2 meters tall. The rock misses the building on its way down, and is observed to strike the ground 4.00 seconds after being thrown.
 
  Neglect any effects of air resistance. With what speed was the rock thrown?

Question 2

A transverse wave is traveling on a string stretched along the horizontal x-axis. The equation for the vertical displacement y of the string is given by y = 0.0020 cos(15x - 52t), where all quantities are in SI units.
 
  The maximum speed of a particle of the string is closest to
  A) 0.33 m/s. B) 0.43 m/s. C) 0.64 m/s. D) 0.53 m/s. E) 0.74 m/s.

[djofnc]

Answer to Question 1

3.05 m/s

Answer to Question 2

A

[joe]

Wow, this really help

[daiying98]

Thanks for the timely response, appreciate it