Energy Conservations and Transformations with Two Objects

Click For Summary

Homework Help Overview

The problem involves two masses connected by a string over a frictionless pulley, with a focus on energy conservation and transformations as one mass descends and the other ascends. The original poster is trying to determine the speed of the system when one mass reaches the ground.

Discussion Character

  • Exploratory, Conceptual clarification, Problem interpretation

Approaches and Questions Raised

  • The original poster attempts to list known values and equations but expresses uncertainty about how to incorporate both masses into their calculations. Some participants suggest considering the gravitational potential energy changes for each mass and combining them. Others question the use of the energy conservation equation.

Discussion Status

The discussion is ongoing, with participants providing guidance on the relevance of energy conservation principles. There is an exploration of how to apply these principles to the specific scenario, but no consensus has been reached on the exact approach to take.

Contextual Notes

Participants are working within the constraints of the problem's setup, including the assumption of a frictionless pulley and the need to account for both masses in the energy calculations.

alexphysics
Messages
3
Reaction score
0

Homework Statement



Masses of 350g and 175g are attached by a light string and hanging straight down from a light frictionless pulley. The 350g mass is 1.5m above the ground. What speed will the system have when the 350g mass hits the ground.

My attempt at a data list is (after i drew a diagram)

mA=350g
mB=175g
vA1=0m/s
vA2=?
hA1=1.5m
hA2=0m

Assume Gravity is 9.8m/s [down]



Homework Equations



Wnc=E2-E1
E2=E1



The Attempt at a Solution



I can not figure out how to figure out this question as I am not sure how my formula should look to include both masses in the situation.
 
Physics news on Phys.org
The two masses are connected by a string, so they have the same speed. And if one goes down, the other goes up by the same distance.

How does the gravitational potential energy change, when the masses move? Figure out the change for each mass and add them.
 
so should i be using the formula E2=E1 to figure it out?
 
Sure. Where E is the total mechanical energy.
 

Similar threads

How Do Kinetic Energies Compare When Two Bodies Have Equal Momentum?
  • · Replies 9 ·
Replies
9
Views
2K
Conservation of momentum/energy of stacked balls
  • · Replies 6 ·
Replies
6
Views
5K
Conservation of Energy: Finding the Speed of a Falling Ball
  • · Replies 1 ·
Replies
1
Views
1K
How Do You Calculate Velocity and Height Using Conservation of Energy?
  • · Replies 9 ·
Replies
9
Views
2K
Velocity of two identical masses over a frictionless pulley
  • · Replies 3 ·
Replies
3
Views
3K
What is the energy conservation principle in a two masses and pulley problem?
  • · Replies 33 ·
2
Replies
33
Views
4K
Momentum and kinetic energy of collision between two identical railroad cars
  • · Replies 1 ·
Replies
1
Views
14K
Collision Conservation of Energy
  • · Replies 5 ·
Replies
5
Views
2K
Calculating Final Velocity in Free Fall from Given Displacement and Acceleration
  • · Replies 2 ·
Replies
2
Views
3K
Two objects acceleration problem
  • · Replies 3 ·
Replies
3
Views
1K