Filip: Oops. I typed 0.5 instead of 0.6 in my calculator for the speed of the rocket. L = 28.0, not 30.3. I think everything else is correct.
Andrew: Thanks for showing me another way to calculate t.
Homework Statement
A 35 m long rocket is receding at 0.6c. From the point of view of a stationary observer, how long does it take for light to travel (a) from the bottom of the rocket to the top and (b) from the top to the bottom?
Homework Equations
t = d/v
L = L0 / gamma
The Attempt at a...
Homework Statement
A particle moving at 0.95c travels 10 m, as measured by a stationary observer, and then disappears. How long did the particle live (a) from the point of view of the observer and (b) from the point of view of the particle?
Homework Equations
t = d/v
d = d0/gamma
The Attempt...
Homework Statement
A particle moves with constant velocity along the curve r = e^(θ) and z = r (cylindrical coordinates). The speed, v, is constant.
a) Calculate the velocity and acceleration of the particle in terms of θ and v.
b) Show that the velocity and acceleration are perpendicular...
There are no radii given. So it's best to assume it's truly frictionless. The problem is difficult enough without friction. If you or anyone else sees any mistakes in my equations I'd appreciate any help you could provide.
In the equation for the acceleration of M2, I forgot to multiply it by g.
I uploaded a more recent photo of my attempted solution. It's in the OP above the original photo.
1. Homework Statement
What is the acceleration of m1? There is no friction so the pulleys don't rotate. The top rope is connected to the ceiling.
Homework Equations
See photo. I think my formula for the acceleration of M2 is only right if m1 = m2 and wrong in all other situations, but I'm not...
Let's say a spaceship made of a transparent material moving past the Earth in a straight line at a constant speed of 0.99 c, and it's at its minimum distance from Earth. If a light is turned on in the middle of the ship, for an observer on Earth will the light move towards the front of the ship...
Thank you very much haruspex and Doc Al. I just finished deriving the correct formula and answering the question. The minimum angle is 4.6 radians. Since this is greater than pi radians, the rope has to loop an extra time around the rod so the angle will be 3 pi radians (since the rope is...
I forgot to mention that the rope is massless in the problem. I believe that in this case the normal force per unit angle will be constant along the section of rope touching the rod, right?
Homework Statement
A 100 kg man holds up a 1000 kg weight by holding on to a rope that is wrapped around a stationary horizontal rod whose other end is tied to the suspended weight. If the coefficient of static friction between the rope and rod is 0.5, what is the minimum number of times that...
Gauss's law (to answer the bolded). It seems to me that this law implies that corona discharge around power lines should be impossible.
I understand that there's a non-radial electric field inside current carrying conductors; if there wasn't, there'd be no current (unless they were...
This article doesn't even try to explain why the electric field outside a circuit is non-zero, let alone why it can become so high in some situations that corona discharge occurs. Can someone who understands this please explain it or provide an appropriate link?
I understand corona discharge in electrostatic situations, but in circuits without capacitors/gaps, I don't understand why it can ever happen (since as far as I know, the electric field is virtually 0 in the air around such a circuit). So why is there corona discharge around high-voltage power...
Oh ya! I didn't think about self-inductance; I think that's the next thing I learn about. Thank you.
This should be taught better in 1st year physics courses.