Question

The 2-lb collar has a speed of 5 ft>s at A. The attached spring has an unstretched length of 2 ft and a stiffness of k = 10 lb>ft. If the collar moves over the smooth rod, determine its speed when it reaches point B, the normal force of the rod on the collar, and the rate of decrease in its speed.

y = 4.5-1x2 2 4.5 ft k-10 lb/ft 3 ft Prob. 14-88

Answer 1

By work energy theorem

$W_{spring}+ W_{gravity } = KE$

$\frac{1}{2}kx^2+ mgH = \frac{1}{2}mv^2$

$0.5*10*[(4.5 - 2)^2 - (3 - 2)^2]+ 2*4.5 = \frac{1}{2}*2*v^2$

$26.25 + 9 = v^2$

$v = 5.94 ft/s$