Question

consider a simple pendulum of length 1m. its bob performsa a circular motion in horizontal plane with its string making an angle 60 with the vertical. The centripetal acceleration experienced by the bob is
a.17.3 m/s^2 b.5.8 m/s^2
c.10m/s^2 d.5m/s^2

Answer 1

Answer:

answer: d  

reason:  

1/2m v square+ mgl(1-cos theta )= 1/2 MV square

or v square+ 2 gl( 1- cos theta )= v square

or  

v square+2 ×10×0.5(1-1/2)=9

or  

v square=9-5=4

v = 2 m/ s inverse

Answer 2

Given that,

Length = 1 m

Angle = 60 °

We need to calculate the centripetal acceleration

Using formula of centripetal acceleration

$a_{r}=\omega^2 r$

$a_{r}=\dfrac{gl\sin\theta}{l\cos\theta}$

$a_{r}=gl\tan\theta$

Where, g = acceleration due to gravity

l = length

Put the value into the formula

$a_{r}=10\times1\tan60$

$a_{r}=17.3\ m/s^2$

Hence, The centripetal acceleration experienced by the bob is 17.3 m/s².

(a) is correct option