Physics help please.

Question

the ball launcher from a classic pinball machine has a spring that has a force of 1.2 N /cm. the surface on which the ball moves is inclined to 10.0 degrees with respect to horizontal. the spring is initially compressed 5.00 cm find the launching speed of a 100 g ball when thee plunger is released. friction and the mass of the plunger are negligible.

ok so what i got f = kx

k = 1.2 n/cm

m = 100g

x = 5 cm

f = 1.2 (5) = 6

Vi = v cos 10

how do i find v? how do i proceed what is the initial launching speed of the ball?

Answer 1

The 10 degrees is given so that u can find the fraction of the weight of the ball that is acting against the spring. Since there is an inclination of 10 degrees, and since the ball's mass = 1 kg (SI unit), 1sin 10 N is against the spring.        so 6 - sin 10 = 5.83 N = the total force exerted on the ball. From here on I am not sure but I'm guessing that u have to use F = ma:

5.83 = 1a = a = 5.83 meters per second squared... etc. However I suspect that you need to use energy equations rather than equations of motion for this question (i.e kinetic energy = 1/2 mv(sqaured...) But unfortunately I'm no expert at energy sorry... good luck!