# Energy Conservations and Transformations with Two Objects

• alexphysics
In summary, two masses of 350g and 175g are attached by a light string and hanging from a frictionless pulley. The 350g mass is initially at a height of 1.5m above the ground. The question is asking for the final speed of the system when the 350g mass hits the ground. Using the formula E2=E1, the change in gravitational potential energy for each mass can be calculated and added together to determine the final speed.
alexphysics

## 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]

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.

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.

## 1. What is energy conservation and transformation?

Energy conservation is the principle that energy cannot be created or destroyed, but can only be transformed from one form to another. In the context of two objects, energy conservation means that the total energy of the two objects remains constant, even as it may change forms.

## 2. How does energy conservation apply to two objects?

In a system with two objects, the total energy of the system remains constant. This means that if one object gains energy, the other object must lose an equal amount of energy in order to maintain the total energy of the system.

## 3. What are some examples of energy transformations between two objects?

Some examples of energy transformations between two objects include a pendulum swinging back and forth, a ball bouncing on the ground, and a car colliding with another car.

## 4. How is the conservation of energy related to the law of thermodynamics?

The conservation of energy is the first law of thermodynamics, which states that energy cannot be created or destroyed, only transformed. This law applies to all systems, including those with two objects where energy is constantly being exchanged between the two objects.

## 5. What factors influence the efficiency of energy transformations between two objects?

The efficiency of energy transformations between two objects depends on factors such as the types of energy involved, the properties of the objects, and the presence of external forces such as friction. The ideal efficiency of energy transformations is 100%, but in reality, there will always be some energy lost in the form of heat or other forms of energy.

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