(a) The spring constant is 500 N/m.
(b) The extension of the spring when 25 N force is applied is 0.05 m.
(c) The applied force to cause an extension of 5 mm is 2.5 N.
The given parameters:
The spring constant is calculated as follows;
[tex]F = kx\\\\k = \frac{F}{x} \\\\k = \frac{10}{20 \times 10^{-3}} \\\\k = 500 \ N/m[/tex]
The extension of the spring when 25 N force is applied is calculated as follows;
[tex]F = kx\\\\x = \frac{F}{k} \\\\x = \frac{25}{500} \\\\x = 0.05 \ m[/tex]
The applied force to cause an extension of 5 mm is calculated as follows;
[tex]F = kx\\\\F = 500 \times 5 \times 10^{-3}\\\\F = 2.5 \ N[/tex]
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