Suppose that 2.3 of work is needed to stretch a spring from its natural length of 36 cm to a length of 47 cm. (a) How much work (in J) is needed to stretch the spring from 38 cm to 42 cm? (Round your answer to two decimal places.) 0.26 X J (b) How far beyond its natural length (in cm) will a force of 20 N keep the spring stretched? (Round your answer one decimal place.) x cm

Suppose that 2.3 of work is needed to stretch a spring from its natural length of 36 cm to a length of 47 cm. (a) How much work (in J) is needed to stretch the spring from 38 cm to 42 cm? (Round your answer to two decimal places.) 0.26 X J (b) How far beyond its natural length (in cm) will a force of 20 N keep the spring stretched? (Round your answer one decimal place.) x cm