# What does the Dynamometer show?

1. Aug 15, 2013

### Fishingaxe

1. The problem statement, all variables and given/known data

What does this dynamometer show?

http://imageshack.us/photo/my-images/826/0uqz.png/

That's pretty much the entire problem, I realize that this is utterly pathetic to post here but I lack the very foundations in physics and after googling this "problem" I still haven't gotten any results, I've thought about it as well and I've only come to one conclusion:
2. Relevant equations

3. The attempt at a solution
My conlusion is that it has a weight of 3kg pulling it down, that's it. I know it's stupid to say that it's my conclusion after hours of googling and thinking about it, and I probably come across as a retard and rightly so. If this is such a simple problem and doesn't deserve to be posted here then I apologize. I figured if I'm having problem with a "problem" why not ask the geniuses?

PS: I tried to upload the picture using the insert photo feature but somehow it came out blank so I decided to use insert link.
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Aug 15, 2013

### Staff: Mentor

Hi Fishingaxe, [Broken]

I don't see a dynomometer. To me that looks like a spring balance for measuring a force (or a weight).

"Why not ask the geniuses?" indeed! But while waiting for them to answer, why not search via google for a physics equation that relates weight to mass.

Last edited by a moderator: May 6, 2017
3. Aug 15, 2013

### Basic_Physics

It measures a force in dynes, the unit of force in the cgs (in which measurements are made in centimeters, grams and seconds units) system. 1 dyne is a force of 1 gram cm/s2. In the S.I. unit of measurement the unit of force is newtons which is 1 kg m/s2.

100 000 dyne = 1 newton

4. Aug 15, 2013

### CWatters

From Wikipedia..

"A dynamometer or "dyno" for short, is a device for measuring force, moment of force (torque), or power."

So fishingaxe will need to tell us what his dynamometer is designed to measure (force, torque or power).

Force is usually measured in Newtons
Torque in Newton Meters
Power in Watts.

or related units.

5. Aug 15, 2013

### Fishingaxe

Thank you very much for your answer, so if I understand this correctly the solution is as follows:

1 dyne = 1 gram cm/s2

The weight is 3kgs which is 3000 grams and that is 3000 dynes so that should be 0.03N? Since 100.000 dyne = 1N.

Or is 1N = 1kg m/s2 so the force is 3N?

I am sorry about still being confused.

6. Aug 15, 2013

### Fishingaxe

Hello, I believe it is in Newtons, I study from my home and the assignment I simply downloaded from the schools website, and I have as much information as you got from me. However from overlooking the other physic problems I have I believe it is supposed to be solved in N.

7. Aug 15, 2013

### CWatters

8. Aug 15, 2013

### Fishingaxe

Now I think I got it, thank you.

Solution: F = mass * acceleration. F = 3kg * 9.81m/s2 = 29.43 N.

F = 29.43 N.

Is this correct?

9. Aug 15, 2013

### Basic_Physics

Yes, so the dynamometer will read 29.43 x 105 dynes.
you should actually round this off to one significant digit since the problem only gives 1 significant digit - 3 kg.

10. Aug 15, 2013

### Staff: Mentor

Well done sorting that out!