Question

1. A 61 g firing pin in a horizontal rifle bolt is attached to a spring. The shooter applies an average force of 57 N to compress the spring 4.1 cm.

(a) Calculate the spring constant.   N/m

(b) Ignoring friction, calculate the maximum speed of the pin after the spring is released.

2.An archer uses her bow to aim a 150 g arrow vertically upward. The effective spring constant of the bow at full flex is 990 N/m. When released, the arrow attains a maximum height of 50 m.

(a) Calculate the bow string's maximum displacement.

Answer 1

(a) Spring force will be given as

(b) Work done by the force is equal to the energy stored in the spring hence when it releases, potential will start converting to kinetic hence

2(a) Energy provided to the arrow will be

At maximum height that energy will be converted in gravitational potential energy hence