Answer:
F=248.5W N
Explanation:
Newton's 2nd Law tells us that F=ma. We will use their averages always. The average acceleration the tennis ball experimented is, by definition:
Since we start counting at 0s and the ball departs from rest, this is just 
So we can write:
Where in the last step we have just multiplied and divided by g, the acceleration of gravity. This allows us to introduce the weight of the ball W since W=gm, so we have:
Substituting our values:
Where the average force exerted has been written it terms of the tennis ball's weight W.
Answer:
Explanation:
Given:
- time taken by the sun to complete one revolution,
- radial distance of the sunspot,
<u>Therefore, angular speed of rotation of sun:</u>
<u>Now the tangential velocity of the sunspot can be given by:</u>
Answer:
Either B or D. The answer itself is 2.
Explanation:
The equation for the kinetic energy would be 1/2*mv^2.
When m is doubled, we can plug in 1 and 2 to compare our answers.
Plugging in 1 for mass would give us the answer 1/2*v^2.
Plugging in 2 for mass would give us v^2. This means that the velocity was multiplied by 2, meaning that the answer is it is multiplied by 2.
I am not sure which answer is correct since there seems to be two answer choices with 2 in it, but the answer is either B or D (I will call it ABCD because I do not want to cause confusion by saying 2 multiple times).
I'm not sure about the rest but for question 2:
A theory is an attempt to come up with a big picture of all we know so far. It also drives future research as people do experiments to see if what the theory predicts actually happens. When experiments don’t support the theory, you have to change the theory and try again. That’s how science works. We come up with a “best guess” (theory), and then do research to test it’s accuracy. As we discover contradictions, we adjust the theory to take those into account, and then start testing the validity of the new theory.
