- #1
Tim Wu
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I find this problem kind of tricky. I think it must be a, since a change in momentum of the car causes the same change in momentum of the earth.
Is Conservation of Energy the Key to Solving This Tricky Problem?
- Thread starter Tim Wu
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In summary, the conversation discusses a problem involving momentum and kinetic energy. The group agrees that the change in momentum between the car and the earth is the same, but questions whether the kinetic energy is also the same. Through comparing the formulas, they determine that the kinetic energy gained by the Earth would be much lower due to its larger mass, and conclude that option c is the correct answer.
I find this problem kind of tricky. I think it must be a, since a change in momentum of the car causes the same change in momentum of the earth.
- #2
Doc Al
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That part is correct. But does that imply that the kinetic energy is the same? Compare the formulas for momentum and kinetic energy.Tim Wu said:
- #3
Tim Wu
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Oh yeah! Ek=1/2*m*v^2, and v = p/m, therefore Ek= p^2/2m. Since p is the same for car and Earth but the Earth's mass is way bigger the kinetic energy gained by Earth wud be much lower! So would option c be right?Doc Al said:
- #4
Doc Al
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You got it. Good thinking!Tim Wu said:
FAQ: Is Conservation of Energy the Key to Solving This Tricky Problem?
What is conservation of energy?
Conservation of energy is a fundamental law in physics that states that energy cannot be created or destroyed, but only transformed from one form to another. This means that the total amount of energy in a closed system remains constant over time.
How does conservation of energy apply to everyday life?
In everyday life, conservation of energy can be observed in many ways. For example, when you turn on a light switch, the electrical energy is transformed into light energy. When you ride a bike, your body's chemical energy is converted into kinetic energy. This principle also applies to larger systems, such as the Earth's energy balance, where energy from the sun is converted into heat and fuels the planet's climate.
What are the different forms of energy?
There are many different forms of energy, including kinetic energy (energy of motion), potential energy (stored energy), thermal energy (heat), chemical energy (energy stored in chemical bonds), and electromagnetic energy (light). These forms can be converted into one another, but the total amount of energy remains constant.
How does conservation of energy relate to the laws of thermodynamics?
The first law of thermodynamics is essentially a restatement of the principle of conservation of energy. It states that energy cannot be created or destroyed, only transformed. The second law of thermodynamics states that in any energy transformation, some energy will be lost as heat, resulting in a decrease in the overall quality of energy. Both of these laws are fundamental in understanding and applying the concept of conservation of energy.
What are some real-world applications of conservation of energy?
Conservation of energy has many practical applications, such as in renewable energy sources like solar and wind power. It is also used in the design of energy-efficient buildings and transportation systems. Additionally, conservation of energy is crucial in understanding and predicting natural phenomena, such as weather patterns and climate change.