Instead of moving back and forth, a conical pendulum moves in a circle at consta
ID: 1771617 • Letter: I
Question
Instead of moving back and forth, a conical pendulum moves in a circle at constant speed as its string traces out a cone (see figure below). One such pendulum is constructed with a string of length L = 12.1 cm and bob of mass 0.302 kg. The string makes an angle = 5.72° with the vertical.
(a) What is the radial acceleration of the bob?
(b) What are the horizontal and vertical components of the tension force exerted by the string on the bob? (Assume radially inward to be the positive x axis and vertically upward to be the positive y axis. Express your answer in vector form.)
Explanation / Answer
along horizontal
Fnet = T*sintheta = m*a
T*sintheta = .......(1)
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along vertical
Fnet = 0
T*costheta - m*g = 0
T*costheta = m*g..........(2)
from 1 & 2
tantheta = a/g
a = g*tantheta = 9.8*tan5.72
accelration a = 0.982 m/s^2
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(b)
horizontal component Tx = T*sintheta = m*a = 0.302*0.982 = 0.296 N
vertical component Ty = T*costheta = m*g = 0.302*9.8 = 2.96 N