A small 0.13 kg metal ball is tied to a very light (essentially massless) string
ID: 1368681 • Letter: A
Question
A small 0.13 kg metal ball is tied to a very light (essentially massless) string that is 0.9 m long. The string is attached to the ceiling so as to form a pendulum. The pendulum is set into motion by releasing it from rest at an angle of 60 with the vertical.
a)What is the speed of the ball when it reaches the bottom of the arc?
I have this already as 2.3 m/s
b)What is the centripetal acceleration of the ball at this point? in m/s^2
c)
What is the tension in the string at this point?
Express your answer in newtons to two significant figures.
Explanation / Answer
here,
theta = 60 degree
mass , m = 0.13 kg
l = 0.9 m
v = 2.3 m/s
b)
the centripetal acceleration of the ball at this point , a = v^2/l
a = 2.3 ^2 /0.9
a = 5.88 m/s^2
the centripetal acceleration of the ball at this point is 5.88 m/s^2
c)
the tension in the string , T = m*a + m*g
T = 0.13*( 5.88 + 9.8)
T = 2.04 T
the tension in the string is 2.04 N