Simple Questions Part 2: Q32,33 & 31 - Help Needed!

[Security]

I started a thread called simple questions part 2 (https://www.physicsforums.com/showthread.php?s=&threadid=10036), and there is a section of questions that i still having trouble executing. First off with questions 32 and 33 I know which formula to use but i don't know how to calculate it on paper. For Question 33 The formula is d=1/2at^2 but 9000meters is the only figure given. and with question 32 and the formula being v=at, do I use the whole 14,000 secs or condense it to size for the calculating.

with questions 31 I am not sure at all which formula to use. I am very lost.

 

[Moonbear]

Hi there. I took a look at those problems and some of the help already given to you. I don't think I can clarify #31 any further. Nate seems to have offered up all the answers there are.

For #33, remember acceleration due to gravity is a constant.

For #32, why are you throwing acceleration into the equation? Does the problem say anything about the people accelerating? You're trying to over think that one. What do you mean condense the 14,000 s to size? I don't understand your question. The question refers to speed, not velocity, so you don't need to worry about vectors, so just think of it like a really basic word problem in math.

It sounds like you're well past the level of work that your parents can help you with during homeschooling. You really should talk to them about going to a regular school where you will have access to multiple teachers who each have expertise in their own subjects (nobody can know every subject well enough to teach them all once you're out of elementary school, especially when it has probably been 20 or more years since they last learned some of that stuff).

 

[M98Ranger]

Hi there,

I understand that you are having trouble executing questions 32, 33, and 31 in the thread you started. I will do my best to help you with these questions.

For question 33, the formula to use is d=1/2at^2. The given figure of 9000 meters is the distance traveled, and we need to find the time (t) it took to travel that distance. We can rearrange the formula to solve for t, which would be t=√(2d/a). Plugging in the values, we get t=√(2*9000/9.8) ≈ 42.4 seconds.

For question 32, the formula to use is v=at. Since the time given is 14,000 seconds, we can use the whole value. Plugging in the values, we get v=9.8*14000 ≈ 137,200 m/s.

For question 31, we need to determine which formula to use based on the given information. The formula for velocity (v) is v=d/t, where d is distance and t is time. The formula for acceleration (a) is a=Δv/Δt, where Δv is the change in velocity and Δt is the change in time. So, if you have the values for distance and time, you can use the first formula to calculate velocity. If you have the values for change in velocity and change in time, you can use the second formula to calculate acceleration.

I hope this helps you with your questions. If you are still unsure, please feel free to ask for further clarification. Don't worry, we all get lost sometimes, but with a little help, we can find our way back. Keep up the good work!