67. A 2.00-kg block lies at rest on a frictionless table. A spring, with a spring constant of 100 N/m is attached

to the wall and to the block. A second block of 0.50 kg is placed on top of the first block. The 2.00-kg block is

gently pulled to a position x = +A and released from rest. There is a coefficient of friction of 0.45 between

the two blocks. (a) What is the period of the oscillations? (b) What is the largest amplitude of motion that will

allow the blocks to oscillate without the 0.50-kg block sliding off?