Recent content by alejandro7

Is my result for R correct or should I include the other arm in the calculation (so the forces would be 2 x W/2, 2 x Warm, 2 x R and W)?

The torque that the man has to generate about is shoulder to stop his arms rotating is the reaction force (R) times the distance. But which distance?

Hi. I'm trying to solve this problem but I'm not sure my solution is right: "Suppose that a male gymnast wishes to execute an iron cross during a gymnastics session. The total mass of the gymnast is 60 kg. Each ring supports half of the gymnast's weight. Assume that the weight of one of his...

We define by recursion the set of sets {An:n∈ℕ} this way: A_0=∅ A_n+1=A_n ∪ {A_n}. I want to prove by induction that for all n∈ℕ, the set A_n has n elements and that A_n is transitive (i.e. if x∈y∈A_n, then x∈A_n). My thoughts: for n=0, A_1 = ∅∪ {∅} = {∅} then, for n+1: A_n+2...

It = using spherical coordinates. I will try that.

Oh, my bad. Yes, but is it necessary? What is the best path to follow?

No, there is not optimization involved in the problem. I'm familiar with the pendulum but the relation between vectors (with vector calculus notation) and forces is confusing me.

Hello I'm trying to solve the following problem: "Find the equations of movement of a particle of mass m that slides on the inner surface of a spherical container given by the equation x^2 +y^2 + z^2 = 1, z≤0" I know I have to use F=ma and I've tried derivating the equation but I...

I'm having trouble with the following problem: "Consider the parabolic mirror given by the equation $z=x^2+y^2$. Show that when the rays of light that travel parallel to the $z$ axis pass through the same point when reflected." I'm familiar with the law of reflection but I'm stuck...

Hi Can you please help me with this problem? "What is the maximum size of a set A of logical expressions that only use →, p, q : each pair of elements of A are not equivalent?" I've found 6 different possible truth values. Is this the maximum size? If yes, how do I prove it? Thanks!

Ok I have: e^lim when x-> of ((ln(1-2^x)/x)) L'Hôpital now?

1/x goes down.

Hi, I'm having troubles wiith this problem: limit when x->∞ (1+2^x)^(1/x) I don't know how to proceed (I know I have to use l'Hospital's rule). It's a ∞^0 indetermination. Thanks!