Going upstream: 432 km / 6 hours = 72 km/h
Going downstream: 384 km / 4 hours = 96 km/h
Going upstream against the current means that the effective speed is:
r_boat - r_current = 72
Meanwhile, going downstream with the current means;
r_boat + r_current = 96
Adding both equations (to cancel out r_current) gives:
2r_boat = 72 + 96
r_boat = 84 km/h
Substituting back into one of the original equations: r_current = 12 km/h.
Answer:
33 1/3 lb
Step-by-step explanation:
When the distance between them goes from 8 ft to 12 ft, it is 1.5 times what it was. Then the force will be multiplied by the inverse of the square of this:
(75 lb)×1/(1.5²) = 75/2.25 lb = 33 1/3 lb
At 12 feet apart, the attraction force is 33 1/3 pounds.
To solve this problem you must apply the proccedure shown below:
1. You have that the following information given in the problem above: The<span> photograph is reduced by a scale factor of 3/8 and the original had a length of 20 inches,
2- Therefore you have:
length=20 inches-</span>(20 inches x 3/8)<span>
length=20 inches-7.5 inches
length=12.5 inches
3- Then, as you can see, the answer is: 12.5 inches.</span>
