Work and energy problem feedback

In summary, the conversation discussed a practice question involving a 12 kg wagon being pulled at an angle of 38° above horizontal, and the calculation of the applied force needed to accelerate the wagon from rest to a speed of 2.2 m/s over a distance of 3.4 m. The equation W=ΔE was used to find the force, and the final answer was determined to be 10.8N. There was also a discussion about the use of energy and force in solving the problem.
  • #1
gbaby370
48
0
I'm just starting to cover Work and Energy.

I had a question which asked, "A 12 kg wagon is being pulled at an angle of 38° above horizontal. What force is applied to the wagon if it accelerates from rest to a speed of 2.2 m/s over a distance of 3.4 m?"

For the record this is just a practice question and I am simply posting for feedback if I have made an error somewhere.

Given we have m= 12kg F=? Angle= 38 degrees V1=0 V2=2.2 Δd=3.4

I used the equation;

Work = Change in energy

W=ΔE

FcosθΔd=(0.5)mv2^2-(0.5)mv1^2

I rearranged and got.

F=(0.5)mv2^2/cosθΔd

F=(0.5)(12)(2.2^2)/cos38(3.4)

F=10.8N


How's that look?

The question might seem simple but I've been out of high school for several year and am hoping to go back to school, so I am just trying to ensure I'm remembering all of the fundamentals.
 
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  • #2
This basically what I did to rearrange the equation
 

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  • #3
I don't understand why you are asking about energy when the problem asks about force.

Force equals mass times acceleration so you can easily get the horizontal component of the applied component- the component that causes the acceleration. Then you need to use a little trig to get the applied force- cos(theta) is the horizontal force divided by the applied force- the hypotenuse in your force diagram.
 
  • #4
This question was in the kinetic energy section.

But I think your method, and mine would equal the same thing?
 

Related to Work and energy problem feedback

What is work and energy problem feedback?

Work and energy problem feedback is a method used in science to evaluate the effectiveness of a system or process in converting energy into work. It involves analyzing the inputs and outputs of a system to determine the efficiency of the energy transfer.

Why is work and energy problem feedback important?

Work and energy problem feedback is important because it allows scientists to assess the performance of a system and identify areas for improvement. It also helps in understanding the relationship between energy and work, which is a fundamental concept in physics.

How is work and energy problem feedback used in real-world applications?

Work and energy problem feedback is commonly used in the design and optimization of machines and systems, such as engines, turbines, and power plants. It is also used in renewable energy technologies, such as solar panels and wind turbines, to improve efficiency and output.

What are the key components of work and energy problem feedback?

The key components of work and energy problem feedback include the input energy, the output work, and the efficiency of the system. The input energy is the initial energy put into the system, while the output work is the useful work produced by the system. Efficiency is the ratio of output work to input energy.

What are some common challenges in using work and energy problem feedback?

One common challenge in using work and energy problem feedback is accurately measuring the input energy and output work. Another challenge is accounting for all the factors that may affect the efficiency of a system, such as friction, heat loss, and other forms of energy loss. Additionally, it can be difficult to apply work and energy problem feedback to complex systems with multiple inputs and outputs.

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