Solve Conical Pendulum: Find Speed, Period, Horiz. Comp., Rad. Accel.

[coolskool]

The Conical Pendulum


A small object of mass m is suspended from a string of length L = 1.8 m. The object revolves in a horizontal circle of radius r with constant speed v and angle = 28°

Find the speed of the object.
i found s=v=2.098.

Find the period of revolution, defined as the time interval required to complete one revolution.
i found it to be ... t=2.53

NOW...

For the conical pendulum described above, determine the following if m = 14.0 kg.
(a) the horizontal and vertical components exerted by the string on the object
(b) the radial acceleration of the object.

for H my equation is
T=ma/sin theta

and to find a=s/t
i take what i found in the previous problem right?
so s=v=2.098
and t=2.53?

and for Fv my equation is T=mg/costheta?

and then for part b...mv^2/r...
but what is r?

OKAY i found everything BUT the HORIZONTAL COMPONENT!
HELP

 

[Kurdt]

For the first part I get a slightly different answer for the speed and period. your answers are round about the same as mine so perhaps just using different constants.

For parts a and b, you will have to go back to the circular motion equations and find the horizontal force being exerted on the bob.

part b the equation you have used is for force but you want acceleration. Remember F=ma. Also you should know what r is from the first part of the question. Its simply a matter of trigonometry (i.e. the pendulum string forms a right angled triangle with the vertical and horizontal and you know the hypotenuse and one of the angles).