Answer:
a) 1111.0 seconds
b) 833.3 s
c) Because of proportions
Explanation:
a) Total time of round trip is the sum of time upriver and time downriver

Time upriver is calculated with the net speed of student and 0.500 km:

(Becareful with units 0.5 km= 500m) Similarly of downriver:

So the sum is:

b) Still water does not affect student speed, so total time would be simply:

c) For the upriver trip, student moved half the distance in half speed of the calculation in b), so it kept the same ratio and therefore, same time. So the aditional time is actually the downriver.
Answer:
Equilibrium. • When an object is in equilibrium (either at rest or moving with constant velocity), the net force acting on it zero.
<span>The answer is 6 kg the mass of the second
object. By using Inversely proportional formula it means that (14 kg) (3 m/s</span>²<span>)
= M (7 m/s</span>²<span>). Where M is the mass of the second object. For the
Newton’s second law of motion formula which is: Force = mass x acceleration, we
have:</span>
<span>F = (14 kg) (3 m/s</span>²<span>) = 42 N</span>
Therefore:
<span>42 N = M (7 m/s</span>²)
<span>M = (42 N) / (7 m/s</span>²<span>)</span>
M = 6 kg mass of the second object