TS EAMCET 04 May 2019 Shift 1 Solved Paper

The expression for the apparent frequency when the source is moving towards the observer is given by,
n1=n0⋅‌

v

v−vs

The expression for the apparent frequency when the source is moving away from the observer is given by,
n2=n0⋅‌

v

v+vs

The expression representing the beats heard by the observer is.
x‌‌=n1−n2
‌‌=n0v[‌

1

v−vs

−‌

1

v+vs

]
‌‌=n0v[‌

v+vs−v+vs

v2−vs2

]
x(v2−vs2)‌‌=n0v(2vs)
Further solving it as
x(v2−vs2)=n0v(2vs)
vs2+35000vs−122500=0
The roots of the above quadratic equation is calculated as,
vs‌‌=‌

7

2

m∕s
‌‌=3.5m∕s