In the figure, a 4.0-kg ball is on the end of a 1.6-m rope that ...

[bobbysung]

In the figure, a 4.0-kg ball is on the end of a 1.6-m rope that is fixed at 0. The ball is held at point A, with the rope horizontal, and is given an initial downward velocity.
 
  The ball moves through three quarters of a circle with no friction and arrives at B, with the rope barely under tension. The initial velocity of the ball, at point A, is closest to
 
  A) 4.0 m/s
  B) 5.6 m/s
  C) 6.3 m/s
  D) 6.9 m/s
  E) 7.9 m/s

Question 2

In the figure, a very small toy race car of mass m is released from rest on the loop-the-loop track. If it is released at a height 2R above the floor, how high is it above the floor when it leaves the track, neglecting friction?
 
  A) 1.67 R
  B) 2.00 R
  C) 1.50 R
  D) 1.33 R
  E) 1.25 R

[Joc]

Answer to Question 1

Answer: D

Answer to Question 2

Answer: A

[bobbysung]

Excellent

[Sarahjh]

Gracias!