It takes 3.78 J of work to stretch a spring according to Hooke’s law 14.2 cm from its unconstrained length.
How much extra work is needed to
stretch it another 11.2 cm?
Answer in units of J. Now this sounds so similar to your last question that I’m hesitant to say anything.
remember the other:
stored potential energy = (1/2) kx^2
then
3.78 Joules = 0.5 * k * (0.142) ^ 2
solve for k
now TOTAL work to get to 14.2 + 11.2 or 25.4
= 0.5 * k * (0.254) ^ 2 joules
now subtract 3.78 from that Oh!! I get it, I just had trouble figuring out how to solve to get k, but then I realized it was enough to divide both sides until isolating k by itself. Thanks! You’re welcome.