# Homework Help: Pinball Question

1. Nov 19, 2006

### dan_c_101

In a pinball machine, there is a spring, the further back you pull the spring the faster the ball goes. With variables, h, m, R, K and g, what is the spring constant. To get the ball at its minimum speed to go around the boundries of the pinball machine without falling.

2. Nov 19, 2006

I can't say I understand the problem completely, but I'm pretty much sure you need to use conservation of energy somehow. Hope that helps.

3. Nov 19, 2006

### dan_c_101

What my teacher is asking is basically the equation for x (spring constant). Theres no numbers involved, but im getting really confused.

4. Nov 19, 2006

### Integral

Staff Emeritus
While all of the variables you listed are completely understood by you, they are a total mystery to us. Please define your variables.

Also the minimum speed of the ball is 0, it will not go anywhere at the minimum speed. Please give us a better statement of the problem.

5. Nov 19, 2006

### physics.guru

Your question appears a little vague. Generally, the spring constant is implied by the variable k (dimensions N/m) and x is the displacement of the spring (in meters) from its equilibrium point. In general, the force Fs of the spring is given by:

Fs = -kx

The negative implies the force acts in the opposite direction of the displacement. Some textbooks call this a restoring force.

If you write the entire question down, perhaps we can be more specific to your needs.

Hope this helps.

6. Nov 19, 2006

### dan_c_101

Sorry guys, this is all that my teacher gave our class. h is the height of the pinball table like from the spring to the very top of the pinball table. And there is a spring constant (i think he means the stretch of the spring) so that the ball can go at a velocity that would get it around the boundaries of the pinball table without falling off its path. Sorry I cant be more detailed but thats all the info we were given. m is mass, x is spring constant, g is the acceleration.

7. Nov 19, 2006

### dan_c_101

Your looking for how far does the spring stretch back, not the constant.