Parallel:
M1V1+M2v2=M1V1’+M2V2’
(0.5)(3)+0=(0.5)(cos60)(3)+V2’Cos(x)(0.5)
V2’cos(x)=
Perpendicular:
M1V1+M2v2=M1V1’+M2V2’
0=(0.5)(0.3)(sin60)+V2’sin(x)(0.5)
V2’sin(x)=
And the divide 2 by 1
Which is tan(x)=2/1
And then plug then back into solve, but I don’t think we do it like this because...
I've been researching water bridges and electrowetting to learn the effects of electric fields on water molecules but something continues to confuse me: if polar molecules can only rotate in an electric field, how is the water moving? Anyone familiar with this phenomenon? Any help is greatly...
I can solve this question using relative Velocity or using 2 kinematics equations. But a peer of mine, tried to do it in a different way. He substituted the above said values in the 4 equations and solved for u in terms of t and differentiated them and equated to to 0 to find a maxima. He found...
Hi All
I hope this topic makes sense for this forum and somebody can help me to understand.
This is what I understand (please allow numerical approximations):
1. Electrons move in a conductor at a speed anywhere near the speed of light.
2. Electrons gain actual velocity (drift) only when...
I'm pretty confused by this but I have a few thoughts. Since the sun takes up most of the mass of the solar system, I was thinking maybe I'm really looking for the escape velocity of the sun? So I would use the mass of the sun for M and the radius of the sun for r. My other thought was to add up...
https://ibb.co/jG6n0jZ
The 15 is fine as this is clearly his overall magnitude but then v2 is equated to the horizontal velocity rather than the magnitude.
Hello! So, I was beginning to skim Kleppner and Kolenkow for an upcoming course I’m taking over the summer. I saw this on pg. 17 and was wondering if I’m making a silly mistake in understanding what the book is saying. When they take the derivative of the position function, isn’t the velocity...
I kind of just made up the questions. I realize this is a basic question but my knowledge of physics is very limited.q1 answer
v_left_ball = v_left_ball - v_train
v_right_ball = v_right_ball + v_train
q2 answer
To get the speed from Bob's frame I would use v_Bob = v_Bob + v_Alice
To get the...
@PeroK sent me here based on a discussion starting at https://www.physicsforums.com/threads/some-ideas-on-interstellar-space-travel.1006562/post-6550265.
Summary:
Someone claimed that an accelerated observer's clock (observer at 1g from Earth to halfway to Alpha Centauri, then -1g the rest of...
That was my approach:
$$P_f - P_i = [(m-dm)(v + dv) + dm(u+v+dv)] - [m(v)]$$
$$= mdv - dmv + dmu + dmv = mdv + dmu = 0$$
Since the variation of the rocket's velocity is perpendicular to itself, $$ dv = v d \theta => m v d \theta + dm u = 0$$
So we have $$\frac{dm}{m} = \frac{-v d \theta}{u}$$...
Hi, so I solved this using energy. I also tried solving this using kinematic equations. The issue I am running into s for calculating the Vy of the problem. I am able to find the time it takes the rock to fall using d=(1/2)gt^2. Then, I considered two different ways of going about finding the...
Question:
Galileo released a metal ball from rest so that it could roll down a smooth inclined
plane. The time t taken to roll a distance s was measured. He repeated the
experiment, each time recording the time taken to travel a different fraction of the
distance s.
Write an expression for the...
In this scenario, we have a compressible flow at 0.99 barA pressure and flowing at 300 m/s velocity and is released into 1 barA pressure. Point is, whether the flow can be released at 1 barA or not at the release pressure is higher than the pressure of the compressible fluid inside the tube. And...
Hello to everyone, first of all shame on me I has to ask and can not figure out it by myself...
The problem is I am trying to code game where two homogenous discs with same mass and same diameter, no fricition due to gravitational forces, can collide.
I can figure out the speed and direction...
Hi,
I saw that the group velocity for an electromagnetic wave can be calculate with the following formula
##v_g = v_p + k \frac{d v_p}{dk}##
Thus, since ##v_p = \frac{c}{n} = \frac{\omega}{k}##
Is it correct to say that ##v_g = \frac{c}{n} + k(- \frac{\omega}{k^2})## where ##k =...
If we throw a ball with initial velocity v0, and the ball progresses in a projectile motion, ignoring air resistance, will there be a force in the x direction? If so, what is that force in the x direction's value mathematically? I know there is a force in the y direction due to gravity.
Hello,
I'm considering the "beats" phenomena. I have two plane waves in some medium with a refractive index n(ω), one propagates in a z direction and second in a direction making an angle θ with z axis. Waves have frequencies ω1, ω2 (not necessarily equal) and k-vectors k1, k2 (not necessarily...
We can find the potential energy by finding the potential difference between the two masses. the minimum distance between the two masses is 10 cm. The maximum is 30 cm because they can be 3 string lengths apart as they repulse each other once the string is cut.
So, to get potential difference...
b) My question is here!
0.9v_t = v0 + a*t = a*t
t = 0.9v_t/a
delta_h = v0*t + 0.5*a*t^2 = 0.5*a*t^2 = 0.5*((0.9*v_t)^2)/a =
where a = (-m*g + b*v)/m
delta_h = (0.5*((0.9*v_t)^2)*m)/(-m*g + b*v)
plugging in everything delta_h = 1.65 m which is not what the answer is. Please help
I am trying to solve the problem below. I have previously calculated from 0 to 4 seconds how far the rocket will travel in each second. I am stuck now as to how to start this problem. I have searched but unable to find the answer. Do i need to rearrange this? A is currently 14 which does not get...
We know the net force on the charged particle in the uniform electric field pointing up is mg - qE.
To get acceleration, divide the net force by mass to get g - qE/m
Plug into kinematic equation and get velocity by itself and substitute$$\sqrt{h(2g - \frac{q \sigma}{\epsilon_o m})}$$
hey i don't understand why my answers are incorrect, here is my solution i would like if someone can help me understand what I am doing worng and how i should solve this problem
We think of length and time as the first fundamental quantities and velocity as the first derived quantity but any two determine the third so we would be completely justified in defining velocity as a fundamental quantity and one of length or time as the other, with the remaining being the first...
When a tomato is thrown up with a velocity ##v_0## it’s kinetic energy is 1/2mv_0^2. It will stop at the top and then again comes back to the launch point where it’s kinetic energy will be same as before, 1/2mv_0^2. How is this possible?
Also when we throw the tomato up how can you be so sure...
Using the equations mentioned under this question, I came up with following analysis and directions of velocities on either side of ##x_1##. Also, I'm not sure if there is an easier qualitative way to know the velocity directions rather than do a detailed Calculus based analysis?
A nuclear reactor is built to fuse two hydrogen atoms that are already ionized to protons. However, the electric field of the protons are becoming a significant obstacle. If the reaction was to be defined as H2--> 2H++2e-, if the mass of a proton is mp, the radius of a proton r the charge of an...
A station is orbiting a planet at a distance R1, a moon is orbiting the planet at distance R2 with the period T. The planet itself has a radius rp and a mass mp. We know that when an object adds its velocity at a point in the orbit, the height of the opposite orbit will increase. Determine the...
I tried to write the data I understood from the image:
y0=160m
yf=0
x0=0
x1=192m
I tried to express the total change in time using the position over time equation on the Y direction:
y(t)=y0+v0y*(t2-t1)-0.5a(t2-t1)^2
but then I stuck with 2 variables and didn't know what to do
any help?
Vertical components:
dy = 0m
ay = 9.8m/s^2 [down]
t = 1.34s
V1y = required
V2y = 0
i first tried to find V1y
dy =vi t + 1/2 a t^2
and got V1y = -6.566
then i solved for time of flight
dy =vi t + 1/2 a t^2
0 = -6.566t + 4/9t^2
and for 1.34 seconds
does this mean the time of flight is the...
the v before hitting the ground immediately=4.85m/s
the v after hitting the ground immediately= 3.96m/s
I considered the down positive, then
v= u+at
3.96= 4.85+ (a*0.16)
so a= -5.56m/s*s
The answer is 55m/s*s
The parts that I don't get are why it must be -3.96 and why that velocity becomes...
Here's my list of variables and things to account for:
m=100kg
Wnc=5000J
Wfriction=-500J
-Kinetic energy will be doubled (though I don't know how that plays into it exactly)
-I don't think there's any PE because it's on level ground
My idea of what the equation might be:
Wnc +1/2mv^2initial =...
An object starts from rest and accelerates at 3.0 m/s2 for 4.0 s. Its velocity remains constant for 7.0 s, and it finally comes to rest with uniform deceleration after another 5.0 s. Find the following:
a. the displacement for each stage of the motion
b. the average velocity over the whole time...
If you've seen it, they chose one point in the combustion chamber and the other in the exhaust nozzle. I think they're assuming that we have a gas both places. They say that the pressure in the nozzle is atmospheric pressure, or it you're in outer space, zero. That makes perfect sense...
I know it isn't possible for any mass/massless body to have velocity more than the speed of light in vacuum but what if it was done hypothetically?
As far as I know length and time of an object undergo a transformation so that the laws of physics remain same between observers at rest and...
Hello, this is a repost from a much less-clear question I posted before (link to question: https://www.physicsforums.com/threads/triangles-inside-a-circle-to-represent-raypaths-inside-an-ideal-earth.1011998/#post-6596165).
It's kind of a loaded question, however it can be expressed as triangles...
Since the question says that "velocity along the cylinder axis" and "magnetic field perpendicular to the cylinder axis". So cross product of velocity and magnetic field becomes their magnitude.
##\vec v\times \vec B=||v|| \\ ||B||##
So
##\vec F=qvB##
##mg=qv\frac{\mu_0 nI}{4\pi r}##
At first...
Can someone tell me how to plot/graph velocity in vpython? All the documentation I see just deals with plotting the position of the object, nothing on plotting the velocity.
Initial observer is at rest. So ##x\prime=0##, and according to question they are 10 meter apart. So lorentz transformation becomes
##vt=x##
##v=\frac{x}{t}##
##=\frac{10 \\ \mathrm m}{13\times10^{-9} \mathrm s}##
But I don't get the expected answer. I believe if I had took ##\beta c## instead...
When I try following numbers from internet then I don't get an expected answer.
## \mu_0 = 1.25663706 × 10-6 m kg s^{-2} A^{-2}##
##q =1.60217662 × 10^{-19} coulombs ##
##r=2.82x10^{-15} m##
Velocity of that electron is given in question
##\vec v= 2 \times 10^6 \\ \mathrm{ms^{-1}}##Since...