A block of mass m is attached to the lower end of a light vertical spring of force constant k. The upper end of the spring is fixed. The block is pulled down to compress the spring by a distance x0 and released from rest. Throughout the motion, neglect air resistance.
a. (i) Derive an expression for the speed v of the block when the spring is compressed by a general distance x(0≤x≤x0) during its upward motion.
b. (ii) Using your expression, obtain the maximum speed attained by the block during the subsequent oscillation.
c. (iii) Evaluate the speed when x=0.020m for m=0.40kg, k=150Nm−1 and x0=0.050m. Express your answer correct to two significant figures.