Answer:
147.456077993 Hz
Explanation:
= Frequency of the sonar = 22 kHz
= Velocity of the whale = 4.95 m/s
v = Speed of sound in water = 1482 m/s
The difference in frequency is given by

The difference in frequency is 147.456077993 Hz
Get a pull chord light switch installed in her bathroom by a qualified electrician asap. Meanwhile, keep hands as dry as possible, and try not to go near that switch until it's either been properly earthed, or whatever the problem actually is, and get qualified advice on what the problem is. Don't have wet feet either, and don't stand in puddles of water whilst operating - i she has to - the switch. 250V AC mains can be lethal, and at least painful.
Answer:
33333.35 kg
Explanation:
I got it right on Acellus, rounded to 33300 sigfigs
Total distance = 76+54 = 130km
total time = 2+5 = 7hrs
Av. speed = 130/7 = 18.571km/hr = 18.6 km/h ( 3 sig fig)