Hi. The language here looks as though it's Spanish/Portugese ??? It would help to answer the q if the q were posted in english. I speak a little spanish and french, but it's mostly guesswork.
Answer:
4 km/hr
Explanation:
suppose 's' is Diane's speed with no current.
't' represents time in hrs.
Using the formula:
Distance = speed 's' x time 't'
-> when she swims against the current, equation will be,
5= (s-2)t
t= 5/(s-2)
->when she was swimming with the current, equation is,
15= (s+2) t
t= 15/(s+2)
equating eq(1) and (2)
5/(s-2) = 15/(s+2)
5s + 10 = 15s - 30
40= 10s
s= 40/10
s=4
Therefore, if there were no current, her speed is 4km/hr
Energy is transfered when its moved from one object to another. The rate of energy transfered is called power. Work is the transfer of energy from one object to another.
