List of Topics


 

Machines Feedback

by Ron Kurtus

Readers have sent in a total of 28 comments and questions on Machines issues. They are listed according to date.

You can read them to further your understanding of the subject.



List of next 15 letters

Title

Topic

Country

Class of janglover lever Levers Nigeria
 
Rolling friction in bearings Bearings Kuwait
 
How can we calculate mechanical advantage? General Nigeria
 
Fatylever Levers India
 
Lever at an angle Mechanical Advantage India
 
What is the mechanical advantage of a lever? Levers Pakistan
 
Efficiency of a machine at 100% General Nigeria
 
Classes of different levers Levers Nigeria
 
Improve description of screw Simple Machines USA
 
What is a load? Levers India
 
Using a horizontal lever Mechanical Advantage USA
 
Torque calculations for a bicycle General India
 
Scientific principles behind the zipper? General USA
 

Next 15 letters

 




First 15 letters


Levers

Class of janglover lever

June 24, 2015

Question

Which Class Of Lever Is A Janglover?.

Samuel - Nigeria (26120)

Answer

I am sorry, but I don't know what a Janglover is.

Return to List

Bearings

Rolling friction in bearings

April 9, 2015

Question

The following is a question appeared in one exam and the two answers
given by two different websites for the same are given below

13. Ball bearings are used in bicycles, cars, etc., because__:
A. The actual area of contact between the wheel and axle is increased
B. The effective area of contact between the wheel and axle is increased
C. The effective area of contact between the wheel and axle is reduced
D. None of the statements is correct

Answer: C
The basic premise in friction theory is that anything that reduced the area of contact between the wheel and axle will decrease the friction. Since the ball is a sphere, it only contacts the wheel and axle at a very small point, which helps it spin very smoothly.

Answer: D
Friction is independent of Surface Area

Hashir - Kuwait (25902)

Answer

If a hard object is sliding on a hard surface, the resistance from friction is approximately independent of the surface area in contact, However, ball bearings aren't meant to slide. Instead, they roll, and rolling friction is different and much less than sliding friction.

The reason ball bearings are used in bicycles and cars is so that they can roll around the axle, as opposed to having the wheel slide around the axle.

See: Rolling Friction for more information.

Return to List

General

How can we calculate mechanical advantage?

March 15, 2015

Question

how can we calculate mechanical advantage

Emmanuel - Nigeria (25830)

Answer

There are three types of mechanics advantage: force, distance and speed. Force mechanical advantage is the resistance force or load divided by the effort force required to move the object.

See Mechanical Advantage in Machines.

Return to List

Levers

Fatylever

March 3, 2015

Question

what you mean fatylever? Why it come? And how to get it back to normallever. What are the problems by fatylever

basav - India (25807)

Answer

I have never heard of a fatylever. For normallever, do you mean a normal lever?

Return to List

Mechanical Advantage

Lever at an angle

November 14, 2014

Question

If fulcrum is at centre and both arms of load and effort are equal, but the arm of effort makes an angle 120 degree with the arm of load
Whether forces of load and effort are equal or not.
Thanks

Jagdish - India (25534)

Answer

There are many facts that need to be clearly stated.

I assume the lever is a straight board. If it is bent at 120 degrees, and the distances from the fulcrum to the load and effort are still equal, the forces will still be equal.

Return to List

Levers

What is the mechanical advantage of a lever?

May 20, 2014

Question

what is mechanical advantage of lever? and why mechanical advantage of second order lever is greater than one?

Urshia - Pakistan (24979)

Answer

There are three types of mechanical advantage: force, distance and speed. The mechanical advantage of a lever is the load divided by the effort. See: Mechanical Advantage in Machines for more information.

You always want the mechanical advantage to be greater than 1, depending on whether force, distance or speed, otherwise what is the purpose of the lever?

Return to List

General

Efficiency of a machine at 100%

February 28, 2014

Question

why is the efficiency of a machine is 100 percentage?

jamiu - Nigeria (24565)

Answer

The only time the efficiency of a machine is 100 percent is if there are no losses due to friction, heat, or other forms of energy. However, all machines have some losses and thus have efficiency less that 100%.

See Efficiency of Machines for more information.

Return to List

Levers

Classes of different levers

February 3, 2014

Question

what class of lever did claw hammer and sugar tonge falls into

etinghafuotota - Nigeria (24481)

Answer

With a claw hammer, the fulcrum is between the effort and the load, so it is a Class 1 lever.

With a sugar tong, the effort is between the load and the fulcrum, so it would be a Class 3 lever.

Return to List

Simple Machines

Improve description of screw

September 29, 2013

Question

The description of a Screw could be improved. Proposed enhancement:

"The screw is really an inclined plane that is wrapped around a central axis. It transforms rotational motion and torque into axial motion and force."

Comment: I understand the reference to to the wedge function where the some screws are designed to form the mating thread as they are driven into a material.

George - USA (24064)

Answer

Thanks for your suggestions.

I updated the page with your remarks. I plan to add more detailed pages on the use and function of screws in the near future.

Return to List

Levers

What is a load?

September 24, 2013

Question

My topic is what is load? ( applied machines ) give some extra notes an formula to complete this topics .and some basic concept.

shambhu bhushan - India (24048)

Answer

When you use a lever to lift and object, that object is also called the load.

Return to List

Mechanical Advantage

Using a horizontal lever

September 16, 2013

Question

I am trying to decrease the effort to move an object, with wheels, side ways, (left or right) by means of a straight lever protruding from the back. Are there any different formulas for side movement?
Thanks for your help.

Dan - USA (24018)

Answer

Although illustrations show levers moving a weight or lead in a vertical direction, using a lever to move an object is independent of direction. The "load" for a horizontal lever would often be the resistive force of friction.

Wheels, rollers, or bearings would greatly reduce the required force for moving an object.

Return to List

General

Torque calculations for a bicycle

November 30, 2005

Question

Sir,
I have to try some modifications on bicycle.
For the above porpose I require to know the torque calculations by varing the load. e.g. take load 120kg. and will be the driving torque so that bicycle run at 30k.m.p.h.(kilometers per hr.)

AMIT - India (9161)

Answer

It is not a simple problem, and there is much information you need. If you put a load of 120kg on the bicycle peddle, you first need to know the length of the peddle arm to determine the torque on the sprocket. Then you need to know the gear ratio of the bicycle chain to the rear wheel. Then you need to know the radius of the read wheel. Finally, a bicycle usually requires the rider to drive his legs at a specific speed.

Return to List

General

Scientific principles behind the zipper?

October 15, 2005

Question

What are the scientific principles behind the zipper?

GT - USA (8568)

Answer

The zipper is just a clever series of clasps. I guess you would say it is a series of simple machines.

A history and picture of the first zipper can be seen at:
http://inventors.about.com/library/weekly/aa082497.htm

Return to List

Next 15 letters


Misc


Questions and comments

Do you have any questions, comments, or opinions on this subject? If so, send an email with your feedback. I will try to get back to you as soon as possible.


Share this page

Click on a button to bookmark or share this page through Twitter, Facebook, email, or other services:

 

Students and researchers

The Web address of this page is:
www.school-for-champions.com/sfc/
feedback_course.cfm

Please include it as a link on your website or as a reference in your report, document, or thesis.

Copyright © Restrictions


Where are you now?

School for Champions

Machines Feedback




Subjects in website



Let's make the world a better place

Be the best that you can be.

Use your knowledge and skills to help others succeed.

Don't be wasteful; protect our environment.

You CAN influence the world.





Live Your Life as a Champion:

Take care of your health

Seek knowledge and gain skills

Do excellent work

Be valuable to others

Have utmost character

Be a Champion!



The School for Champions helps you become the type of person who can be called a Champion.