The centripetal force on a 0.82 kg object on the end of a 2.0 massless string being swung in a horizontal circle is 4.0 N. What is the tangential velocity of the object?

The answer I got is 3.1 m/s squared but I don't know how to show the work for it. So please help me.

Combine two concepts:

1. F = ma
2. For objects in circular motion with constant tangential velocity:
a = v^2/R

So:

F = ma = mv^2/R for objects in circular motion with constant tangential velocity

You now have everything you need to deermine the value of v.

so it will be this:

4=v sqaured/ 2
then I get 2.8.

but when I plug it back in the equation v^2/r.. I get 3.9

You didn't read ebaines post well. You combine F=ma and a = v^2/r.

Then you get:



From there, you 'll get your answer as 3.1 m/s^2 (2 sf)

OK but what is the v squared part? Because it doesn't really say. I know the mass and the radius I just don't know how to get the velocity

Starting with the formula we gave you:



Raarrange to get by itself:



and take the square root of both sides:



You have valius for and , so you can solve for . Your answer will in units of meters/sec (NOT meters per second squared, as you had in your original post)

Quote:

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Originally Posted by ebaines

Starting with the formula we gave you:



Raarrange to get by itself:



and take the square root of both sides:



You have valius for and , so you can solve for . Your answer will in units of meters/sec (NOT meters per second squared, as you had in your original post)

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Thank you so much I was looking for this :)