Calculating Tension and Speed in a Centripetal Force Problem

[kengreen]

Homework Statement

A model airplane whose mass is 875 grams flies in a horizontal circle of radius 3.46 m at the end of a string which is at an angle 10.5 degrees below the horizontal. Find:

a) the tension in the string
b) the speed of the airplane

Homework Equations

Fc=T=mv^2/r Ac=v^2/r

The Attempt at a Solution

im not sure if i am given enough information to solve this problem because i don't have the acceleration or velocity

 

[Tzim]

You have.I think you could try to analyze the forces to their components and make a relation between the vertical component of tension and the weight.

 

[Tzim]

I hope i helped

 

[kengreen]

i think the vertical component of tension has to cancel the weight? am i correct in where i a m going with this.

 

[Tzim]

yeah that's very good that's the idea

 

[Tzim]

I am sorry i misguide you.Vertical component of tension cannot cancel the weight because they are both pointing down unless i misunderstood the picture.could yuo please draw me an image of the ecxercise?

 

[Tzim]

if this is the case then what i told you is correct.That should be the case bacouse otherwise it would drop

 

[kengreen]

okay well i have the answer to the first question because i talked to my professor but i just don't understand how this is the answer. he said that it is 47.1 N.

 

[Tzim]

Could you draw me the excercise please?

 

[kengreen]

there is no picture. its just a word problem. the thing that is throwing me off is that in the problem it states that the end of the string is at an angle 10.5 degrees below the horizontal.

 

[Tzim]

If the draw is the one i made you then it is correct the 47.1.Approximatelly.Tsin10.5=Mg

 

[Tzim]

I donnot know it should say above or else it could not be possible to rotate it would fall.ask your teacher about it

 

[kengreen]

thank you very much

 

[Tzim]

I donnot think i helped you very much but ok thanks