Question

A small ball with a mass of 30.0 g is loaded into a spring gun, compressing the spring by 13.0 cm. When the trigger is pressed, the ball emerges horizontally from the barrel at a height of 2.30 m above the floor. It then strikes the floor, after traveling a horizontal distance of 2.40 m. Use g = 9.80 m/s2. Assuming all the energy stored in the spring is transferred to the ball, determine the spring constant of the spring.
I tried to use conservation of energy. 1/2 kx^2 = mg(h2-h1). But i don't get the answer.

Answer 1

Are you from BU? haha.

Answer 2

1/2kx^2=1/2mv^2, the v here is vx final, solve for k