A projectile leaves the ground at 150 m/s and reaches a maximum ...

[B]

A projectile leaves the ground at 150 m/s and reaches a maximum height of 0.57 km. If there was no air, at what angle above the horizontal did it leave the ground?
 
  What will be an ideal response?

Question 2

Suppose you slowly, and at constant speed, lift a book weighing 12 N from the floor to a shelf 2 m above the floor. Neglect air resistance. While you are lifting, the net force on the book is
 
  A) less than 12 N, by an amount that depends on the speed of lifting.
  B) more than 12 N, by an amount that depends on the speed of lifting.
  C) 12 N directed upward.
  D) zero.
  E) 12 N directed downward.

[ong527]

Answer to Question 1

45

Answer to Question 2

D

[B]

Wow, this really help

[cpetit11]

Thanks for the timely response, appreciate it