Solving a Pendulum Physics Problem: Finding the Height of a Colliding System

  • Thread starter Thread starter Clutch306
  • Start date Start date
  • Tags Tags
    Pendulum Physics
AI Thread Summary
The pendulum physics problem involves two pendulums, with the left bob held above the right bob, which is released and collides inelastically. The initial gravitational potential energy of the left pendulum is converted into kinetic energy as it swings down. After the collision, the two pendulums stick together and move as one system, allowing for the calculation of their combined height using conservation of energy principles. By equating the initial potential energy to the final potential energy, the maximum height reached by the combined pendulum system is determined to be 0.167 meters. This solution effectively demonstrates the application of mechanical energy conservation in pendulum dynamics.
Clutch306
Messages
7
Reaction score
0
Two pendulums, both of length l = 1.0m, are initially situated as shown in the below figure. The left bob has a mas m1 = 1.0kg and is held a distance d = 0.50m above the center of the right bob, of mass m2 = 2.0kg. The left pendulum is released and strikes the other. Assume that the collsion is completely inelastic, and neglect the mass of the string and frictional effects. How high does the pendulum system rise after the collision?
 

Attachments

Last edited:
Physics news on Phys.org
1. Use conservation of mechanical energy on the swinging pendulum to determine its impact velocity.
2. Use impact analysis to determine the system's velocity after impact.
3. Use conservation of energy of the system to determine the max. displacement.
 


To solve this pendulum physics problem, we can use the conservation of energy principle. Initially, the left pendulum has gravitational potential energy equal to m1*g*d, where g is the acceleration due to gravity and d is the distance the bob is held above the center of the right bob. This potential energy is converted into kinetic energy as the left pendulum swings down and collides with the right pendulum.

Since the collision is completely inelastic, the two pendulums will stick together after the collision and move as one system. The kinetic energy of the system just before the collision is equal to the sum of the kinetic energies of the two individual pendulums. This can be calculated using the formula 1/2*m*v^2, where m is the mass and v is the velocity of each pendulum.

After the collision, the combined pendulum system will rise to a certain height h, where all the energy is now in the form of gravitational potential energy. Using the same formula as before, m*g*h, we can equate the initial potential energy to the final potential energy and solve for h.

m1*g*d = (m1+m2)*g*h

Substituting in the given values, we get:

1.0kg*9.8m/s^2*0.50m = (1.0kg+2.0kg)*9.8m/s^2*h

4.9 = 3*9.8*h

h = 4.9/29.4 = 0.167m

Therefore, the combined pendulum system will rise to a height of 0.167m after the collision. This is the final answer to the problem.
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'Collision of a bullet on a rod-string system: query'
In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top