The only force acting on an object moving along the x-axis is the ...

[dalyningkenk]

The only force acting on an object moving along the x-axis is the conservative force given by F(x) = (2.00 N/m)x + (1.00 N/m3)x3.
 
  (a) What is the change in potential energy when the object moves from x = 1.00 m to x = 2.00 m?
  (b) What is the change in kinetic energy when the object moves from x = 1.00 m to x = 2.00 m?
  What will be an ideal response?

Question 2

A 1.37-kg block is held in place against the spring by a 74-N horizontal external force (see the figure).
 
  The external force is removed, and the block is projected with a velocity v1 = 1.2 m/s upon separation from the spring. The block descends a ramp and has a velocity at the bottom. The track is frictionless between points A and B. The block enters a rough section at B, extending to E. The coefficient of kinetic friction over this section is 0.24. The velocity of the block is at C. The block moves on to D, where it stops. The initial compression of the spring is closest to
 
  A) 2.7 cm.
  B) 1.4 cm.
  C) 0.96 cm.
  D) 5.3 cm.
  E) 3.6 cm.

[lcapri7]

Answer to Question 1

Answer: (a) -6.75 J (b) 6.75 J

Answer to Question 2

Answer: A

[dalyningkenk]

Wow, this really help

[dyrone]

Gracias!