Under the action of load F1, the length of a string is L1 and that under F2, is L2. the original length of the wire is__________
A. [L1F1 - L2F2] / [F1 + F2]
B. [L1F2 - L2F1] / [F1 - F2]
C. [L1F2 - L2F1] / [F2 - F1]
D. [L1F2 - L2F1] / [F1 + F2]
Answer:C
Under the action of load F1, the length of a string is L1 and that under F2, is L2. the original length of the wire is__________
A. [L1F1 - L2F2] / [F1 + F2] B. [L1F2 - L2F1] / [F1 - F2] C. [L1F2 - L2F1] / [F2 - F1] D. [L1F2 - L2F1] / [F1 + F2]