A 31 kg child uses a pogo stick to bounce up and down. The spring constant, k, of the toy equals 8,700 N/m. (a) By how much would the spring be compressed by the child if she simply balanced herself vertically on the pedals of the stick? (Give your answer in cm.)  cm (b) How much energy (in J) is stored in the spring under this circumstance?  J

A 90-gram mass is placed on a vertically oriented spring that then is stretched 0.5 meters below its equilibrium position and released.  If the spring constant is 200 N/m, how fast will the mass be moving when it reaches the equilibrium position?  Hint:  You cannot ignore the change in gravitational potential energy in this problem.  Please give your answer in units of m/s, however, do not explicitly include units when typing your answer into the answer box.  Including actual units will result in your answer being incorrectly scored.

spring constant = 638 N/m.mass = 2.7 kgh = 2.9 mangle = 24 degrees.Note: Assume there is no friction.   How far does the spring compress in m when the mass stops?

A spring is stretched 35.2 cm beyond its equilibrium length. How much energy has been transferred to the spring, if the spring constant is 32.6 N/cm? [Note the units!] E = _J