A heavy ball of mass M is suspended from the ceiling of a car by alight string of mass m (m<<M). When the car is at rest, the speed of transverse waves in the string is 60 ms^{−1}. When the car has acceleration, a the waves-speed increases to 60.5ms^{−1}, the value of a, in terms of gravitational acceleration g, is closest to :

A heavy ball of mass M is suspended from the ceiling of a car by alight string of mass m (m<<M). When the car is at rest, the speed of transverse waves in the string is 60 ms^{−1}. When the car has acceleration, a the waves-speed increases to 60.5ms^{−1}, the value of a, in terms of gravitational acceleration g, is closest to :