Homework Help: physics

Posted by Adam on Wednesday, May 23, 2012 at 11:45am.

A 0.700-kg ball is on the end of a rope that is 2.20 m in length. The ball and rope are attached to a pole and the entire apparatus, including the pole, rotates about the pole's symmetry axis. The rope makes an angle of 70.0° with respect to the vertical as shown. What is the tangential speed of the ball?

I got this:counterbalanced by the horizontal component of rope tension:
m*g*sin(70)

r=2.2*sin(70)
So here's the result
using g=9.81
v=sin(70)*sqrt(2.2*9.81)
v=4.36 m/s but its wrong could someone please help me out. Thank you and sorry for reposting.

physics - bobpursley, Wednesday, May 23, 2012 at 12:02pm
If I visulize the situation,

mg*sintheta=mv^2/r.

Now if the pole movement is small, then r= length*sinTheta

mg(sinTheta)=mv^2/length*sinTheta

v= sinTheta*sqrt (g*lengthrope)

that is what you have in theequation, but not what you calculated. Recalculate
physics - Adam, Wednesday, May 23, 2012 at 1:04pm
Sorry I keep recalculating, but i keep getting 4.36 m/s and thats wrong I don't know what I am doing wrong.
physics - bobpursley, Wednesday, May 23, 2012 at 2:35pm
sqrt(g*lengthrope)=4.64
sin70deg=hmmmm.

Ok, without a picture, I am not certain of where the angle is.

If the angle is measured from the downward vertical to the slanted rope, then sin70 is correct.

Answer this Question

Related Questions

physics - A 0.700-kg ball is on the end of a rope that is 0.90 m in length. The ...
physics - A 0.700-kg ball is on the end of a rope that is 2.20 m in length. The ...
physics - A 0.700-kg ball is on the end of a rope that is 2.20 m in length. The ...
physics - An athlete swings a 4.30 kg ball horizontally on the end of a rope. ...
physics - In preparation for a demonstration on conservation of energy, a ...
Physics - An athlete swings a 3.46 kg ball horizontally on the end of a rope. ...
physics - In preparation for a demonstration on conservation of energy, a ...
physics - A bowling ball weighing 71.8 N is attached to the ceiling by a rope of...
physics - An athlete swings a 3.06 kg ball horizontally on the end of a rope. ...
Physics to drwls question to answer given earlier - A 0.700-kg ball is on the ...

For Further Reading

First Name:
School Subject:
Answer: