Answer:
B. Cant stop things from going wrong.
Explanation:
To me it's the only reasonable answer...
Send wave from your location to the object and wait until echo is back.
Measure the time taken.
If you know the speed of wave (say sound wave), than just multiply by half time taken wave to return
Answer:
Explanation:
A )
speed of swimming in still water is given by the expression
distance / time
= 50 / 25
= 2 m /s
In lane 1 , 1.2 cm/s current is flowing in the direction that the swimmers are going so swimmers will cover distance at the rate of 2 + 1.2 = 3.2 m /s.
time to cover distance of 50 m in lane 1
= distance / speed
= 50 / 3.2 = 15.625 s
In lane 8 , 1.2 cm/s current is flowing against the direction that the swimmers are going so swimmers will cover distance at the rate of 2 - 1.2 = .8 m /s.
time to cover distance of 50 m in lane 1
= distance / speed
= 50 / .8 = 62.5 s
