Free Physics Tutor

hi

Thu, 25 Apr 2013 09:59:49 -0700

Hello

jtotheizzoe: explore-blog: Neil deGrasse Tyson moderates a...

Thu, 25 Apr 2013 09:54:04 -0700

explore-blog:

Neil deGrasse Tyson moderates a mind-bending debate on the existence of “nothing”

Looking for a way to add a few wrinkles to your brain? Check out the debate at the link above.
One of my favorite passages, on how calculus fundamentally altered philosophy:
“The crucial notion of the calculus is the notion of the infinitesimal — the infinitely small. And what is the infinitesimal? It’s not nothing — but it’s not quite something, either. It somehow mediates between finitude and nothingness. … You have to have a temperamental attraction to dangerous ideas, and the infinitesimal is considered to be an extremely dangerous idea.”
Calculus: It’s a dangerous weapon?

Hi physics tutori! How are the energy levels of Be 3+ related to netural hydrogen? Estimate values if possible. Thanks!

Sat, 30 Mar 2013 23:16:38 -0700

So! An ionization energy problem. Well, an electron energy level problem, which is related. As...

Assume a speedster superhero traveling at or above 350 km/h, massing 88 kg, impacts an average adult human male who is standing still. How many bones are broken, and does the average adult human male survive the impact? (Assume the speedster has mystical forces keeping him safe.)

Sat, 23 Mar 2013 18:25:13 -0700

Most of his bones get pulverized/pulped, and hell no he won’t survive. Assuming the speedster...

Hi, physics tutor! Do you think you could explain in layman's terms what a positron is?

Sat, 23 Mar 2013 17:37:00 -0700

Simplest answer: a positron is just like an electron but with a positive electrical charge. (image...

A person is sled-riding down a hill that is 15.0 ft high. starting at the top with a speed of 10.0 ft/s, the sled reaches the bottom with a speed of 25.0 ft/s. (A) determine whether mechanical energy has been conserved. (B) why might mechanical energy not be conserved? What are the equations that you think I should use?

Mon, 18 Mar 2013 22:33:09 -0700

So this person starts at the top with potential energy due to height and kinetic energy due to...

A beautiful, musical end to Pi day.

Thu, 14 Mar 2013 19:00:45 -0700

A beautiful, musical end to Pi day.

More ways to think about pi.

Thu, 14 Mar 2013 17:01:03 -0700

More ways to think about pi.

Happy Pi day everybody! Here’s definition of the number Pi...

Thu, 14 Mar 2013 13:29:58 -0700

Happy Pi day everybody!

Here’s definition of the number Pi for you. I hope it’s delicious.

cthulhu-with-a-fez: rayrayslife: thenimbus: stringmouse: I...

Thu, 14 Mar 2013 13:26:28 -0700

cthulhu-with-a-fez:

rayrayslife:

thenimbus:

stringmouse:

I feel like I’m getting mixed signals from you, physics.

Absolutely Incredible

#WHAT IS HAPPENING

The little machine is vibrating the molecules of the water at a certain frequency and the stream lets us see the wave of that frequency.

I fucking love physics

FUCKING WATERBENDING IS WHAT IT IS

The earlier comment is nearly right. In fact, the frequency of the machine’s vibration has a **wavelength** in air that is visible because of the water passing through it.

What factor accounts for the uniform climates of many coastal areas?

Thu, 07 Mar 2013 23:19:00 -0800

The one thing that coastal areas have in common is that they’re on the coast. That is, they’re next...

A particle has constant acceleration vector ⃗a with components ax = 2.9 m/s2 and ay = −2.6 m/s2. Its initial velocity vector ⃗v0 (at time t0 = 0) has components vx0 = 2.6 m/s and vy0 = 2.4 m/s.What is the particle’s speed at time t = 6 s? Answer in units of m/s.

Sun, 24 Feb 2013 18:33:02 -0800

This is a wonderful little problem, since it is mostly set up for you already. v = v0 + at, right?...

A ball is shot out of a canon that is at the edge of a desk. The desk is .53m high and the ball hits 1.48m away. The canon is aimed 45 degrees from the horizon. Calculate for initial velocity.

Sun, 24 Feb 2013 18:29:40 -0800

So there are two parts to this problem, the x direction and the y direction. Because the cannon was...

fuckyeahfluiddynamics: When two liquid jets collide, they can...

Thu, 21 Feb 2013 13:21:07 -0800

fuckyeahfluiddynamics:

When two liquid jets collide, they can form an array of shapes ranging from a chain-like stream or a liquid sheet to a fishbone-type structure of periodic droplets. This series of images show the collision of two viscoelastic jets—in which polymer additives give the fluids elasticity properties unlike those of familiar Newtonian fluids like water. The jet velocities increase with each image, changing the behavior from a fluid chain (a and b); to a fishbone structure (c and d); to a smooth liquid sheet (e); to a fluttering sheet (f and g); to a disintegrating ruffled sheet (h), and finally a violently flapping sheet (i and j). The behavior of such jets is of particular interest in problems of atomization, where it can be desirable to break an incoming stream of liquid up into droplets as quickly as possible. (Photo credit: S. Jung et al.)

In between asks, so here’s a lovely for you!

Light passing through a given medium is observed to travel at 2 x 10^8 m/s. What is the index of refraction for this medium? (I actually have NO IDEA how to solve this- I just got this unit and my teacher's been absent since monday, so 1) how do I solve this, and 2) what is the 'index of refraction??)

Tue, 12 Feb 2013 19:57:54 -0800

I’ll answer #2 first if you don’t mind. The index of refraction n is the degree to...

Give the charge, mass and magnitude of weight for 31 moles of a sodium ion with 2 extra electrons. (Avogadro's number is 6.02x1023 and the fundametal charge is 1.602x10-19 C.

Fri, 08 Feb 2013 17:43:23 -0800

So this problem is basically in two parts. figure out the charge, mass and magnitude of weight for a...

n-a-s-a: Visualisation of galaxies from the ESO GOODS...

Tue, 05 Feb 2013 16:12:00 -0800

n-a-s-a:

Visualisation of galaxies from the ESO GOODS spectroscopic campaign

Credit: ESO/L. Calçada/ESO-GOODS team

It’s been a while since I just gave you some pretty to look at.

If a doorknob were placed in the center of a door rather than at the edge, how much more force would be needed to produce the same torque for opening the door?

Tue, 05 Feb 2013 15:12:04 -0800

If you look at the previous answer, R and F are each proportional to τ. That means they are...

In what direction should a force be applied to obtain the maximum torque?

Tue, 05 Feb 2013 15:10:25 -0800

So the equation for torque is τ = RF sin θ where θ is the angle between the direction of R (away...

can you explain momentum and impulse?

Tue, 05 Feb 2013 13:44:04 -0800

Momentum, or mass times velocity, is how important a moving object is in a collision. A baseball...