Search: To find out answers to a specific question, copy a representative sentence from the question and paste the sentence in the search form and search it. The results show the most related questions and yours may be in there. Feel free to share LeiAcademy.org with other teachers and students.  
To discourage spam, only registered users can ask questions.

Welcome to Physics Homework and Study Help, where you can ask questions and receive help on learning physics. We currently focus on helping questions in introductory level college physics and high school AP Physics courses.
To discourage spam, only registered users can ask questions.

Facebook Twitter Google

Welcome to Physics Homework Help Page on LeiAcademy.org

Feel free to ask a question and also answer questions others asked. Answering others' questions can in turn help one's own understanding and build a warm healthy community for learning. The followings list a few things that might be helpful for you to effectively obtain help on specific physics homework or practice problems.  

Search: To find out answers to a specific questions, copy a representative sentence from the question and paste the whole sentence in the search form and search it. The results will show the most related questions and yours may be in there

Browse: To find out what have been discussed, asked or answered, put in a few key words in the search form and search for related questions, answers, and or solutions. Or you can click the related tags or other tabs to find useful information there. 

You can also write professional-looking equations using Latex codes (see details here).

This site is hosted on LeiAcademy.org, which will continue to add new resources for learning. Feel free to share this with other teachers and students.  

Question 3 Quiz Week 9

0 votes
169 views
Question 3 Quiz Week 9

I don't have the correct answers for this/any quiz.

A basketball of mass m dropped from a certain height hits the ground with a downward speed v(1) and bounces back with an upward speed v(2) leaving the ground. Ignoreair resistance during the process. What is the impulse applied by the ground to the metal ground.

I don't want the answer, but rather to correct my method of solving (if my answer is wrong) because this is what I'll have during the exam.

Delta(P)=Impulse

mv(2)-mv(1)=I    But here I pick the downward direction to be +ve; therfore v(2) is actually -v(2)

-m(v2+v1)=I and since downward is postive; Impulse is upward and m(v1+v2) option d

 

Correct or wrong?
asked Oct 27, 2013 in Intro College Physics by anonymous

1 Answer

0 votes

If you pick downward as positive, then ||v_2|| is negative and ||v_1|| is positive. So your ||\Delta P|| would be negative too -- a negative P2 minus a positive P1 gives a total negative ||\Delta P||, which means an upward ||\Delta P||. In this case, d is correct. 

In addition, think about the forces the ground applied on the ball -- the force is also in negative direction so upward.  

answered Oct 27, 2013 by PhysicsDude (21,750 points)
web counter
...