Work out the following problem:
A vehicle is fitted with an ultrasonic distance sensor as part of a parking assistance system which provides echolocation while the driver is reversing the vehicle. It emits an ultrasonic wave (about \(40\ kHz\)) which is reflected by an obstacle. When the warning beep starts sounding at a distance of \(2.4\ m\) from the obstacle, how much time is taken by the ultrasonic wave to travel to the obstacle and come back? Assume the speed of ultrasonic waves in air to be \(345\ m/s\).
The time taken by the ultrasonic waves to travel and come back \(=\) \(s\)
[Note: Enter your answer upto three decimal values]