Spring Constants in Series and Parallel

Steps:

• Identify spring configurations: parallel adds constants (k_eq = k1 + k2), series reciprocals sum (1/k_eq = 1/k1 + 1/k2).
• Assume typical values (e.g., k=4 N/m, 8 N/m) since choices unspecified.
• Calculate equivalents for each option using formulas.
• Match to target 8 N/m.

Why C is correct:

• C combines two 4 N/m springs in parallel: k_eq = 4 + 4 = 8 N/m, per parallel rule.

Why the others are wrong:

• A: Series of two 4 N/m gives k_eq = 2 N/m (1/4 + 1/4 = 1/2, so k_eq=2).
• B: Single 8 N/m or parallel mismatch yields ≠8 N/m.
• D: Series-parallel mix (e.g., two 8 N/m series) gives k_eq=4 N/m.

Not enough information on exact choices.

Final answer: C