An 8.0-kg block is released from rest, with v1 = 0.00 m/s, on a ...

[bclement10]

An 8.0-kg block is released from rest, with v1 = 0.00 m/s, on a rough incline, as shown in the figure.
 
  The block moves a distance of 1.6-m down the incline, in a time interval of 0.80 s, and acquires a velocity of v2 = 4.0 m/s. How much work does gravity do on the block during this process?
 
  A) +81 J
  B) +100 J
  C) +120 J
  D) -81 J
  E) -100 J

Question 2

The plot in the figure shows the potential energy of a particle, due to the force exerted on it by another particle, as a function of distance. At which of the three points labeled in the figure is the magnitude of the force on the particle greatest?
 
  A) point X
  B) point Y
  C) point Z

[strudel15]

Answer to Question 1

Answer: A

Answer to Question 2

Answer: A

[bclement10]

Excellent

[Dinolord]

Gracias!