A motorcycle starts from rest and accelerates along a straight line at `2.2(m)/(s^2)`. The speed of sound is `330(m)/(s)`. A siren at the starting point remains stationary. When the driver hears the frequency of the siren at `90%` of when motorcycle is stationary, the distance travelled by the motorcyclist is

Options

A. 123.75 m
B. 247.5 m
C. 495m
D. 990m

Answer

B

Explanation

Let `V_(m)` be the velocity of motorcyclist and V be the velocity of sound.
`v'=(90)/(100)v_(0)=(v_(0)(V-V_(m)))/(V) implies 9V=10V-10V_(m)`
`V_(m)=(V)/(10), V_(m)^(2)-0=2as=(V^(2))/(100)`
`S=(V^(2))/(200a)=((330)^(2))/(200xx2.2)=247.5m`