- #1
EnricoHendro
- 80
- 11
- Homework Statement
- A ball of mass m is connected to two rubber bands, each of length L, each under tension T. The ball is displaced by a small distance y perpendicular to the length of the rubber bands. Assuming the tension does not change, show that the restoring force is -(2T/L)y
- Relevant Equations
- F=-(2T/L)y
Hello there, I am wondering, in this solution, I guessed that the restoring force is given by that equation in the problem because the vertical component of the force acting on the ball is -2Tsin(x). since sin(x) = y/L with L being the hypotenuse part of the triangle formed by displacing the ball vertically upward. as shown in the figure. I get that intuitively, the restoring force involves only the tension of the rubber band, but why don't we also consider the force of gravity? isn't gravity also somehow act on the system? Or we just ignore it because the gravity is countered by the upward tension of the rubber band?