A close-coiled helical spring has a stiffness of 10 𝑁/𝑚𝑚. The length of the spring when fully compressed with adjacent coils in contact is 400 𝑚𝑚. The ratio of spring wire and coil diameter is 1/10 and the modulus of rigidity of the material of the spring is 80 GPa. The diameter of the spring wire and the mean diameter of the coils will respectively, be:
A. 10 𝑚𝑚 and 100 𝑚𝑚
B. 15 𝑚𝑚 and 150 𝑚𝑚
C. 20 𝑚𝑚 and 200 𝑚𝑚
D. 25 𝑚𝑚 and 250 𝑚𝑚
Answer:C
A close-coiled helical spring has a stiffness of 10 𝑁/𝑚𝑚. The length of the spring when fully compressed with adjacent coils in contact is 400 𝑚𝑚. The ratio of spring wire and coil diameter is 1/10 and the modulus of rigidity of the material of the spring is 80 GPa. The diameter of the spring wire and the mean diameter of the coils will respectively, be:
A. 10 𝑚𝑚 and 100 𝑚𝑚 B. 15 𝑚𝑚 and 150 𝑚𝑚 C. 20 𝑚𝑚 and 200 𝑚𝑚 D. 25 𝑚𝑚 and 250 𝑚𝑚