A. Average speed is weighted mean (1 × 2 + 2 × 3 + 3 × 5 + 4 × 7 + 3 × 9 + 2 × 12.5)/15 = (2 + 6 + 15 + 28 + 27 + 25)/15 = 103/15 = 6.867 b. RMS is square root of 1/15 times sum of squares of speeds Sum of squares is 4 + 9 + 9 + 25 + 25 + 25 + 49 + 49 + 49 + 49 + 81 + 81 + 81 +156.25 + 156.25 = 848.5
c. RMS speed = √(848.5/15) = 7.521
Most likely the speed is the peak in the speed distribution, which is 7.
Before you start working on any motion problem, YOU decide which direction you're going to call 'positive'. Everybody almost always calls UP positive, and the acceleration of gravity points down, so it winds up negative. But you could just as well call DOWN the positive direction. Then, the cannonball is fired with a negative vertical speed, and the acceleration of gravity eventually robs all of its negative speed, and makes it start falling in the positive direction. The whole thing is your choice.
The surface temperature of the star increases when it changes its colour changes from red to blue.
Blue>white>yellow>orange>red
The given series is the temperature decreasing order of stars. Now our sun is considered as a yellow star.
The answer is Column, however if you want to know the scientific word for it, it is also known as a group
(extra fact, a row is called a period)
