Physics ???

Question

A small metal ball is suspended from the ceiling by a thread of negligible mass. The ball is then set in motion in a horizontal circle so theat the thread describes a cone. The acceleration of gravity is 9.8 m/s2. The angle is 26 degrees. The distance is 1.7m and the mass is 6.2 kg.
a)What is the speed of the ball when it is in circular motion ?
b)How long does it take T period for the ball to rotate once around the axis ?

Answer 1

a) the vertical component of tension acts horizontally towards the centre of the cirle Tsin 26 so this provids the centripetal force
Tsin 26=(mv .v)/r ..................eqn 1
note .: mv.v/r is the centripetal force
the horizotal component is equal and acts in opposite direction to the weight of the ball (w acts downward and this acts upward)
so Tcos26=mg ......................eqn 2
divide eqn 1 by eqn 2 ,you get tan 26=v.v/rg
solve for v
NB : v.v is v squared
i cosidered the distance you said as the height from the ceiling to the centre of the circle,though am not sure of it or may be is the distance from the bob to the centre of the cicle,so it is the radius.
so draw the conical diagram and deduce this
sin 26=r/1.7m and you wll get the value of r

b) when the ball rotates once around the cirle ,the distance travelled is equal to the circumference of the circle
so distance is 2*pie*r
v=dispalacement(diatance)/time
velocity is from the part a's answer,and now you have distanace so you can calculate for period T

Answer 2

Do your own homework... or post this under homework assistance.... this is easy.... but you should say which angle is 26 degs if you want to be sure of the answer.