Calculate Force Exerted Using Simple Machines

  • Thread starter pvpanther05
  • Start date
  • Tags
    Machines
In summary: NIn summary, the efficiency of a pulley system is 73%. By using pulleys, a mass of 58 kg can be raised to a height of 3.0 m with a force of 129.77 N, if the string is pulled for 18.0 m.
  • #1
pvpanther05
1
0
I totally do not understand how to do this. I missed this day in class and the teacher hasn't had time to explain it to me. Could someone help?

The efficiency of a pulley system is 73%. The pulleys are used to raise a mass of 58 kg to a height of 3.0 m. WHat force is exerted on the string of the pulley systen if the string is pulled for 18.0 m in order to raise the mass of the required height?


Thanks in advance
 
Physics news on Phys.org
  • #2
Originally posted by pvpanther05
The efficiency of a pulley system is 73%. The pulleys are used to raise a mass of 58 kg to a height of 3.0 m. WHat force is exerted on the string of the pulley systen if the string is pulled for 18.0 m in order to raise the mass of the required height?

The way pullies work is by doing an equivalent amount of work by decreasing the amount of force needed and increasing the distance the force is applied over.
work = work
[tex]F_1d_1 = F_2d_2[/tex]

Efficiency is always what you get out divided by what you put in. I'll use a little "e" to express efficiency.
e = out/in
e*in = out

Now just fill in values

[tex]eF_1d_1 = F_2d_2[/tex]

[tex](0.73)F_1(18.0) = (58)(9.8)(3)[/tex]

[tex]F_1 = 129.77[/tex]
 
Last edited:
  • #3
for any help!

Calculating force exerted using simple machines can be a bit confusing, but with some practice, it can become easier to understand. In this case, we are dealing with a pulley system that has an efficiency of 73%. This means that 73% of the input force is converted into output force. To find the force exerted on the string of the pulley system, we will use the formula: Output force = Input force x Efficiency.

In this problem, the output force is the force exerted on the string, and the input force is the force needed to lift the mass. We know that the mass being lifted is 58 kg and the height it needs to be raised is 3.0 m. This means that the work being done is equal to the mass (58 kg) multiplied by the gravitational acceleration (9.8 m/s^2) multiplied by the height (3.0 m). So, the work done is 58 x 9.8 x 3.0 = 1,702.8 Joules.

Now, we can use the efficiency of the pulley system (73%) to find the input force needed. We know that 73% of the input force will be converted into output force, so we can set up the equation: 0.73 x Input force = 1,702.8 Joules. Solving for the input force, we get 1,702.8 / 0.73 = 2,332.6 Joules.

Therefore, the force exerted on the string of the pulley system is 2,332.6 Joules. I hope this helps to clarify the concept of calculating force using simple machines. If you have any further questions, please do not hesitate to ask your teacher or a classmate for help. Practice makes perfect, so keep trying and you will soon understand it better. Best of luck!
 

1. How do you calculate force exerted using simple machines?

The formula for calculating force exerted using simple machines is force = effort arm length / resistance arm length. This means that the force exerted by the simple machine is equal to the length of the effort arm divided by the length of the resistance arm.

2. What are the different types of simple machines?

There are six types of simple machines: the lever, wheel and axle, pulley, inclined plane, wedge, and screw. Each type of simple machine has a specific function and can be used to make work easier.

3. How does the angle of the incline affect the force exerted by an inclined plane?

The steeper the angle of the incline, the smaller the force needed to lift an object. This is because the force is spread out over a longer distance, making it easier to lift the object. However, the trade-off is that the object will have to be moved a longer distance to reach its destination.

4. Can simple machines increase the amount of work done?

No, simple machines cannot increase the amount of work done. They can only make the work easier by changing the direction or magnitude of the force needed to do the work.

5. How does the number of pulleys affect the force exerted by a pulley system?

The more pulleys in a system, the less force is needed to lift an object. This is because each pulley reduces the amount of force needed by a fraction. For example, a system with two pulleys will reduce the force needed by half, while a system with three pulleys will reduce the force needed by one-third.

Similar threads

  • Introductory Physics Homework Help
Replies
26
Views
3K
  • Introductory Physics Homework Help
Replies
8
Views
2K
  • Introductory Physics Homework Help
Replies
2
Views
793
  • Introductory Physics Homework Help
Replies
10
Views
1K
  • Introductory Physics Homework Help
Replies
3
Views
4K
  • Introductory Physics Homework Help
Replies
5
Views
2K
  • Introductory Physics Homework Help
Replies
13
Views
2K
  • Introductory Physics Homework Help
Replies
5
Views
3K
  • Introductory Physics Homework Help
Replies
3
Views
5K
  • Introductory Physics Homework Help
Replies
6
Views
3K
Back
Top