Question

Question #1ad48

Answer 1

Time period will decrease by 6 %

Explanation:

Suppose,the initial length of the pendulum was `100l` and time period was `T1`

So,we can write,
`T1 =2pisqrt(100l/g)`

If,length is decreased by 10 %, new length becomes `90l and if time period is now`T2# then we can write,

`T2 = 2pisqrt(90l/g)`

Dividing `T2` by `T1` we get,
`(T2)/(T1) = sqrt(90/100)`
Or, `(T2)/(T1)=0.94`
Or, `1-(T2)/(T1) = 1-0.94`
Or, `(T1 - T2)/(T1) = 0.06`
So, `(del T)/(T1) *100 = 6`

Answer 2

See the explanation below

Explanation:

The period of a pendulum of `"length"=l` is

`T=2pisqrt(l/g)`

The new length of the pendulum is

`L=0.9l`

The new period is

`T_N=2pisqrt((0.9l)/g)`

`T_N=(sqrt0.9)2pisqrt(l/g)`

`T_N=sqrt(0.9)T`

The new period is `T_N=0.95T`