# Search results

1. ### Heat energy change when gas compressed

Homework Statement One mole of an ideal gas is in a container with a moveable piston. A 100 N force moves the piston down 1 m; the compression is isothermal. Does 100 J of energy leave the gas or enter the gas? Homework Equations W=Fd U=Q-W=Q-P(Vf-Vi) The Attempt at a Solution...
2. ### Calculus-based relationships in electrostatics

Homework Statement I know for example that a=dv/dt and v=dx/dt. I was wondering whether there are similar relationships for things in electrostatics. I have to internalize all of these formulas (for electrostatics), so I was hoping to understand them in a calculus-based sense in order to...
3. ### Chemistry Most likely carbons for nucleophilic attack on a molecule

Homework Statement I've attached a picture of the molecule. The question: at which molecules (s) would it be likely that there would be a nucleophilic attack? Homework Equations The Attempt at a Solution The answer key says a and c, only. However, I think that b is nucleophilic because...
4. ### Force and acceleration in object at rest

Homework Statement An object is at rest and stays at rest, but a rope attached to it is pulling with increasing force. What is the acceleration? Homework Equations F=ma The Attempt at a Solution The solution is that acceleration is constant and 0. Obviously a= dv/dt =0, since...
5. ### Program to Pick Out Files From List

Hi Everyone! This is my first question for programming. I have very little experience, so if you could explain as simply as possible. I have a list of output that actually looks like this: # Query: 2678.m000169 conserved hypothetical protein # Database: EST_matched_Genome.fas.txt...
6. ### Linear Algebra Proof

Homework Statement Suppose S,T ∈ L(V) and S is invertible. Prove that if p ∈ P(F) is a polynomial, then p(S*T*S-1)=S*p(T)*S-1. Homework Equations none The Attempt at a Solution Suppose by contradiction that for any p ∈ P(F), p(S*T*S-1)≠S*p(T)*S-1 for any p ∈ P(F). Since this is true for...
7. ### Four 100 kg people are holding a 1200 kg inflated balloon

four 100 kg people are holding a 1200 kg inflated balloon by means of four ropes. three people let go and the balloon accelerates upward at 2 m/ s/s. what is the tension in the rope the last person is holding?
8. ### Are all groups nonempty?

Are all groups nonempty? If so, is it because all groups have an identity (element)?
9. ### Linear Proofs

Hello, A(rB) = r(AB) =(rA)B where r is a real scalar and A and B are appropriately sized matrices. How to even start? A(rbij)=A(rB), but then you can't reassociate... Also, a formal proof for Tr(AT)=Tr(A)? It doesn't seem like enough to say the diagonal entries are unaffected by...
10. ### Proof of the The Division Algorithm

This is going to be kind of a long post, and I'm citing the author because it's directly from a textbook, but I'm assuming this proof is standard and I won't be doing anything unethical. I'm basically going to post it with my questions interrupting the text. I'm not sure how he got from some...
11. ### Help! Well-ordering principle

Hi! First ever class of Modern Algebra today. I have a question about the well-ordering principle, introduced in class. This seems awfully foreign to me, as I haven't had a single theoretical math class. I'm worried that this question is super stupid so I elected to post it anonymously to the...
12. ### Abstract Algebra

Hello, I just took ordinary diff eq and I've had calc III and linear algebra, but I'm worried about taking Modern Algebra or Real Analysis next semester because I have no experience writing proofs. The linear algebra class was all computation on tests and homework (we did see some proofs on...