a snowball rolls off a barn roof that slopes downwards at an angle of 40 degrees. the edge of the roof is 14m above the ground and the snowball has a speed of 7ms-1 as it rolls off the roof
(a) how far from the edge of the barn does the snowball strike the ground if it doesnt strike anything else.

cant seem to get the answer which is 6.93m :\

 

a snowball rolls off a barn roof that slopes downwards at an angle of 40 degrees. the edge of the roof is 14m above the ground and the snowball has a speed of 7ms-1 as it rolls off the roof
(a) how far from the edge of the barn does the snowball strike the ground if it doesnt strike anything else.

cant seem to get the answer which is 6.93m :\

You have to show some effort before we can help you. What equations do you know for solving this type of problem?

Also, we need to know your background. This problem is trivial if calculus is applied, but if you don't know how to use calculus, we'll take another approach.

 

HINT:
do the decomposition in x and y. note that there is no acceleration in x but there is acceleration in y (due gravity).

 

Note that there is some extraneous data in the problem, and that you probably intended to approximate the diameter of the snowball as 0.

 

Note that there is some extraneous data in the problem, and that you probably intended to approximate the diameter of the snowball as 0.

I don't see any extraneous data, but I agree there are some unspoken assumptions that are implied.

 

i think he's gone...


assuming positive direction in X axis is away from barn wall, positive direction in Y axis is up and 40deg is measured from horizontal, since roof is sloping down this is actually -40deg:


Vo=7m/s
g=-9.8m/s
.....
X=...=6.93m

 

You are not supposed to solve homework problems for the OP.

Why did you do this against the terms of service agreement?

 

hello steve,

i removed bulk of the post to please you.
as for TOS, which TOS you are referring to?
the only one i know is here and it does not even include word "solution" or "homework":
http://www.allaboutcircuits.com/l_tos.html

same with "replying to a post":
http://forum.allaboutcircuits.com/faq.php?faq=vb3_reading_posting#faq_vb3_replying

there sure are many policies and restrictions on this forum and i'm far from saint but can you please enlighten me with specific term(s) i violated?

 

hello steve,

i removed bulk of the post to please you.
as for TOS, which TOS you are referring to?
the only one i know is here and it does not even include word "solution" or "homework":
http://www.allaboutcircuits.com/l_tos.html

same with "replying to a post":
http://forum.allaboutcircuits.com/faq.php?faq=vb3_reading_posting#faq_vb3_replying

there sure are many policies and restrictions on this forum and i'm far from saint but can you please enlighten me with specific term(s) i violated?

If you are not aware of our policy to not encourage abuse of our help, it's OK. That's why I pointed it out.

You are correct that it is not in the terms of service, nor in the replying to post sections. I just assumed it was, going from (faulty) memory remembering back to when I joined. Instead let's refer to the guidelines for posting homework which the OP must obey, as follows.

"When posting a request for homework/coursework/assignment help, you must provide details of your attempts at the questions. Any thread that just posts up a copy of the questions without any attempts on the part of the opening poster will be directed to this thread and will be given 48 hours to satisfy the requirements detailed within."

Also, please note my first comment in this thread.

"You have to show some effort before we can help you. What equations do you know for solving this type of problem?"

Here I'm notifying the OP of his requirement to follow the guidelines. When one member does this, other members should wait for a response. As you say, he is probably not coming back. He either figured it out himself, or is lurking as an anonymous user hoping one of us will violate our own policies. I don't think we should encourage cheating. We used to see this happen, and then once the person got the answer, he would delete the original question and run. Bill has since prevented this by limiting the ability of new users to delete posts.

 

Problem is, this is not the homework thread. It probably should be moved, whatcha think?

 

Problem is, this is not the homework thread. It probably should be moved, whatcha think?

I think that is a moderator's call whether to move it, but it is a homework thread wherever it lies. Hence it should be treated the same in either place. Otherwise, students will exploit the loophole in the system.

Anyway, this is my final straw as far as helping new users with homework. I'll help established users with a track record for coming back and interacting properly. I've even noted some regular users that have deleted some of their questions after getting answers. As I find them, they go on to my ignore list.

 

I don't see any extraneous data, but I agree there are some unspoken assumptions that are implied.

Actually I think you are right, I was a bit to hasty. Actually I think all but the simplest problems are improved by extraneous data, more like real life.

 

... I think all but the simplest problems are improved by extraneous data, more like real life.

I agree completely. Too many problems corral the student into a path to the solution with the data given in a perfect form. Real world problem solving is much more difficult.

 

I've even noted some regular users that have deleted some of their questions after getting answers. As I find them, they go on to my ignore list.

I promise that if anyone ever answers the question I asked in my very first post to the forum that I will not delete it! Promise! ;-)

.