Answer:
Option e) 320 s
Explanation:
Here, distance = 3.0 km = 3000 m
The velocity of boat when it is going upstream;
Upstream velocity = velocity of boat in still water - velocity of river flow
So, Upstream velocity 
So,Time to go upstream
The velocity of boat when it is going downstream;
Downstream velocity = velocity of boat in still water + velocity of river flow
So, Downstream velocity 
So,Time to go downstream
So, total time (t) = 
Option E is the correct answer.
Iso-kinetic exercises cannot be performed at home by an individual because they require specific machines that enable to exercise at a constant speed with professional guidance.
<u>Explanation
:</u>
Iso-kinetic exercises are that kind of training regimes that require a constant pace to strengthen your muscles with the help of machines with significant specifications.
The machines involved in iso-kinetic exercises control your pace with variable resistance throughout the session and hence, it’s not a cup of tea for an individual to trace his/her performances and the respective improvements.
So, before going for a iso-kinetic schedule, be sure to have a word with your physiotherapist to train well with the machines under the specifications that can better suit your body and its requirements.
Answer:
True, when it evaporates heat goes down, because it’s up the the sky.
Facts: In order for water to evaporate, hydrogen bonds must be broken. Water's heat of vaporization is 540 cal/g.
Because of the need for so much energy to evaporate, as water leaves the surface from which it is evaporating and removes a lot of heat with it.
