Going upstream against the current gives a net speed equivalent to the speed at still water minus the speed of the current. Consequently, the speed downstream gives a net speed equal to the speed at still water plus the speed of the current, making it travel faster. The solution is:
UPSTREAM
v = 20 - 1.5 = 18.5 km/h
t = 30 mins or 0.5 hours
distance = 18.5km/h (0.5 h) = 9.25 km
DOWNSTREAM
for the same distance of 9.25 km:
v = 20 + 1.5 = 21.5 km/h
t = 9.25km / 21.5 km/h = 0.43 hours or 25.8 mins = 26 mins --> FINAL ANS.
Hi there! Hopefully this helps!
Answer: A force applied to a machine to an object is the <em>effort force</em>.
The waste products of a nuclear fission power plant can best be described as radioactive waste.
These are the by-products from the processes carried out that produce nuclear energy. This type of waste is highly dangerous. A lot of attention has to be paid to the collection and disposal of this waste as it must not reach any near by water bodies for example. It can be deadly for life.
You need to draw two lines from the head of the arrow: one parallel to the axis (which will be bent) and the other one passing through the center of the converging lens <span>(which will continue straight) </span>and see where they intersect.
If the arrow is at an infinite distance, the image will be point-like in F.
If the arrow is at a distance greater than 2F, the image will be upside down between F and 2F.
If the arrow is at a distance of 2F, the image will be upside down in 2F.
If the arrow is at a distance between F and 2F, the image will be upside down beyond 2F.
If the arrow is at a distance F, all rays proceed parallel to each other and no image is formed.
If the arrow is at a distance smaller than F, the image will be virtual.
Therefore, the correct matches are 1B, 2C, 3D, and 4A.
