Where should I begin with this problem?

  • Thread starter jimmyboykun
  • Start date
In summary, the conversation discusses calculating the work done by pushing a wooden crate across a floor and the work done by friction on the crate. The solution involves using the kinetic coefficient of friction and multiplying it by the weight and acceleration of the crate, then multiplying by the displacement to find the work done. It is important to note the negative value for the work done by friction and to round the answer to two significant figures.
  • #1
jimmyboykun
39
0

Homework Statement



You are pushing a 150-kg wooden crate in a straight line a distance of 4.5 m across a wooden floor at constant speed. The static and kinetic coefficients of friction are 0.42 and 0.30, respectively. What is the work done by you on the crate? and What is the work done by friction on the crate?

I understand that with constant speed meas that my acceleration is zero, but after that I am lost.

Homework Equations





The Attempt at a Solution

 
Physics news on Phys.org
  • #2
Show your work.
 
  • #3
ok here's what I did work is W=F*s.

I multiply 0.30(kinetic energy) because the crate is in motion by 150kg by 9.81m/s^2 which gave me 441.45N as my frictional force. Now I have my force I will multiply it by my displacement to give me my work.

441.45N*4.5m= 1986.525J.

I did it and submitted the answer and received a 1/10 from this problem. What did I do wrong?
 
  • #4
jimmyboykun said:
ok here's what I did work is W=F*s.

I multiply 0.30(kinetic energy) because the crate is in motion by 150kg by 9.81m/s^2 which gave me 441.45N as my frictional force. Now I have my force I will multiply it by my displacement to give me my work.

441.45N*4.5m= 1986.525J.

I did it and submitted the answer and received a 1/10 from this problem. What did I do ##wrong?
Your solution seems fine for "work done by you". "work done by friction" would be negative of the calculated value. Also note that your answer should have only two significant figures. That means answer should have been ##2.0~kJ##. This could be the reason you were marked down.
 
  • #5


I would first suggest breaking down the problem into smaller, more manageable parts. First, you can start by identifying all the given information, such as the mass of the crate, distance traveled, and coefficients of friction. Then, you can use the equation F=ma to calculate the force required to maintain a constant speed. Next, you can use the equation W=Fd to calculate the work done by you on the crate. To determine the work done by friction, you can use the equation W=μFn, where μ is the coefficient of friction and Fn is the normal force. By breaking down the problem and using the appropriate equations, you can successfully solve for the work done by both you and friction on the crate.
 

1. Where do I begin when faced with a complex problem?

The first step in tackling a complex problem is to break it down into smaller, more manageable parts. This will help you to better understand the problem and identify potential solutions.

2. How can I prioritize which aspects of the problem to focus on first?

Prioritizing is key when starting a problem. Consider the urgency and impact of each aspect of the problem and start with the most urgent and impactful parts first.

3. What resources should I gather before starting to solve the problem?

Before diving into solving a problem, it's important to gather all relevant information and resources. This can include data, previous research, and input from experts or stakeholders.

4. How do I avoid getting overwhelmed when starting a difficult problem?

It's common to feel overwhelmed when faced with a difficult problem. To avoid this, try breaking the problem down into smaller tasks and take breaks to recharge your mind. Collaborating with others can also help to ease the burden.

5. What is the best approach for brainstorming and generating ideas to solve the problem?

Brainstorming is a great way to come up with potential solutions for a problem. It's important to create a safe and open environment where everyone's ideas are welcomed. Don't dismiss any ideas, no matter how far-fetched they may seem, as they could lead to a breakthrough solution.

Similar threads

  • Introductory Physics Homework Help
Replies
6
Views
5K
  • Introductory Physics Homework Help
Replies
18
Views
1K
  • Introductory Physics Homework Help
Replies
6
Views
2K
  • Introductory Physics Homework Help
Replies
13
Views
2K
  • Introductory Physics Homework Help
Replies
10
Views
2K
  • Introductory Physics Homework Help
Replies
1
Views
1K
  • Introductory Physics Homework Help
Replies
9
Views
4K
  • Introductory Physics Homework Help
Replies
4
Views
2K
Replies
10
Views
4K
  • Introductory Physics Homework Help
Replies
2
Views
2K
Back
Top