Posted by Harold on .
A block of weight 3.8N is launched up a 30 degree inclined plane of length 2.25m by a spring with spring constant 2.35kN/m and maximum compression 0.10m. The coefficient of kinetic friction is 0.50. How much kinetic energy does it have at the top of the incline?
I get 2.4J am I wrong, if so please help in showing hoe this process woorks out. It would be much appreciated.

Physics 
drwls,
Compute the stored energy in the compressed spring. It is (1/2)k x^2 = 11.75 J. The work done againt friction going to the top of the incline is
W = 3.8N*cos 30*Uk*X = 3.70 J
The work done against gravity going to the top is
3.8N*s1n 30 * X = 4.28 J
The remaining kinetic energy is 3.77 J
Round it off to 3.8