Kinetic Definition and 1000 Threads

Homework Statement So a car owner wants to change his current tires and rims to a wider set of tires and rims for increased handling ability. However, the owner does not want to lose any acceleration performance due to the increased friction of having wider tires. To combat this, the owner...

Hi, I'm trying to get the relativistic kinetic energy, ## T ##, from the work expended, ## W ##, (assuming that the body is at rest initially) and I'm doing it like this (in 1D): \begin{equation} W = T = \int F ds = m \int \frac{d(\gamma u)}{dt}u dt = m\int u d(\gamma u) \end{equation} Where...

Homework Statement This is my first thread in this forum, please forgive me if I made any mistake on posting. Homework Equations I am having difficulty on solving the Problem 5. The Attempt at a Solution The answer I obtained is 1.5MeV, is it correct ?

this question is from the book AP Physics C A mass m1 initially moving at a speed v0 collides with and sticks to a spring attached to a second, initially stationary mass m2. the two masses continue to move to the right on a frictionless surface as the length of the spring oscillates...

Three blocks are connected as shown in the uploaded picture. The strings and friction-less pulleys have negligible masses, and the coefficient of kinetic friction between the 2.0 kg block and the table is 0.17. What is the acceleration of the 2.0 kg block? Homework Equations ∑F = ma The...

Homework Statement A body, which has mass of m = 1 kg , is dropped with a horizontal speed of vo = 20 m/s . What is its kinetic energy after 4 s ? Homework Equations Ek = mv2/2 s = vot + gt2/2 The Attempt at a Solution Is it correct? P. S. There is a mistake: Ek = 3200 J

Homework Statement Is the velocity in the kinetic energy=1/2mv2 average velocity or final velocity?

Hi, I would like to study these two cases: Case A 1/ I turn counterclockwise the ring at w2, this need the energy \frac{1}{2}mr^2w_2^2 with m the mass of the ring 2/ I turn the ring with arm clockwise at w1, this need the energy \frac{1}{2}md^2w_1^2 with d the length of the arm 3/ I eject...

Homework Statement After a lot of searching I can't seem to find a way to solve this. Basically, for a bouncing ball, if I know the dropped height and rebound height in a vacuum. How do I calculate the elasticity between the ball and the floor? Homework Equations K = 1/2 mv2 The Attempt at a...

Homework Statement This is a real basic question I am sure. Maybe I just missed something. so in the book, t = the kinetic energy . only for a pendulum, they add kinetic energy of x dot squared, plus kinetic energy of y dot squared. Homework Equations T = 1/2 m v^2 a^2 + b^2 = c^2 The Attempt...

Homework Statement http://i.imgur.com/hiNHMZZ.jpg - I am struggling with the right-hand page, questions b i, b ii and b iii. I am not sure how to calculate the total amount of kinetic energy transferred to the fluid when given the mass before and after the experiment? Homework Equations EK =...

Hi, I'm new here and I'm having trouble with a question. 1. Homework Statement A 20.0-kg curling stone is released at the hog line and moves 28.35 m [W] to sit on the button and score a point. If the coefficient of kinetic friction between the stone and the ice is 0.00200, what was the...

So I'm trying to model two particle interaction subject only to Lennard Jones potential. I have a specific potential I am using: My problem is forcing the two particles into the potential well. I have the particles at a separation distance of 2.5*10-8. The way I interpret this potential is...

A car of mass 1kg rests on top of a large flat mass of 1,000,000 kg (10^6 kg). They are at rest (relative to the sun) in space. The car has a battery and an electric motor with 100% efficiency. We can assume that when a torque is applied to the wheels, they roll on the surface of the flat mass...

Homework Statement A possible decay mode a of a positive Kaon in the production of three Pions as shown below:. K+ → π+ + π+ + π− Whats is the maximum Kinetic energy that anyone of the pions can have? The kaon is a rest when...

Homework Statement I know that temperature is a measure of the kinetic energy of gas molecules. at a given temperature different gases have the same average kinetic energy. But in solids and liquids there is also potential energy between the close atoms/molecules. how do i know that temperature...

Homework Statement A tall, cylindrical chimney falls over when its base is ruptured. Treat the chimney as a thin rod of length 49.0 m. Answer the following for the instant it makes an angle of 32.0° with the vertical as it falls. (Hint: Use energy considerations, not a torque.) (a) What is the...

Homework Statement A 250 g object is dropped from a height of 150 m. What is the kinetic energy after falling to 100m Homework Equations V2^2 = V1^2 +2ad Ek = 1/2 mv^2 The Attempt at a Solution I used the kinematics equation to find my v2 then I used this to find Ek. I got the answer 120J but...

Homework Statement You stand at rest on one end of a 3.00m long platform (also at rest). The platform is on a smooth friction-less surface. If you walk from one end of the platform to the other at the constant rate of 2.00m/s, what is the kinetic energy of the system (you and the platform)...

Homework Statement An 1100-kg car traveling at 24 m/s coasts through some wet mud in which the net horizontal resistive force exerted on the car from all causes (mostly the force exerted by the mud) is 1.7 x 10^4 N. Determine the car’s speed as it leaves the 18-m-long patch of mud. m = 1,100...

Homework Statement A moving car has 40,000 J of kinetic energy while moving at a speed of 7.0 m/s. A spring-loaded automobile bumper compresses 0.30 m when the car hits a wall and stops. What can you learn about the bumper’s spring using this information? Answer quantitatively and list the...

http://i.imgur.com/0RtN9Ui.png?1 I am trying to find the linear velocity of the sphere as it leaves the cliff. 2. Homework Equations : Moment of inertia of a sphere: I= 2/5 mr2 3. My attempt at a solution: I know that I am supposed to solve this through the conservation of energy, but would...

Homework Statement A charged particle (m=1.673*10^-27 kg) exists in a region with E=10 kV/m in the x direction and B=1T in the y direction. If the particle moves without being deflected calculate its kinetic energy. Homework Equations F=Q(E+u x B) and KE=1/2 mu^2 where u is velocity. This is...

i'm struggling to understand this: an alpha particle is emitted with a kenetic energy T, if we know the value of the depth of the nuclear potential well V, we find the kenetic energy of the alpha particle inside the nuclei by substructing V-T , would you please explain this to me? Thank's

Homework Statement [T,V]=[TV-VT]ψ Homework Equations T=(-ħ2/2μ)∂2/∂x2 V=(1/2)kx2[/B]The Attempt at a Solution [(-ħ2/2μ)∂2/∂x2((1/2)kx2ψ)]-[(1/2)kx2(-ħ2/2μ)∂2/∂x2(ψ)] I think my problem is with executing the chain rule on the first term: (-ħ2/2μ)[x2ψ''+2xψ'+2xψ'+2ψ-x2ψ''][/B] The x2ψ''...

Homework Statement Edward and Jacob, standing face-to-face on a horizontal sheet of frictionless ice, push off each other, causing each to slide backward. Jacob is more massive than Edward. After the push, which of the two is moving faster? Homework Equations Conservation of momentum: Pi = Pf...

Homework Statement A 20.0 kg cannonball is fired from a cannon with a muzzle speed of 1000 m/s at an angle of 37.0° with the horizontal. A second ball is fired at an angle of 90.0°. (a) Use the isolated system model to find the maximum height reached by each ball. (b) What is the total...

I'm going through a physics exercise at high school level. A ball is dropped through a slide and when it reaches the bottom of the slide it will travel horizontally. Assuming there is no energy loss due to friction or air resistance draw a velocity time graph. I tried working it out, the answer...

Hello, I have a question regarding one of the questions on a sample exam I have for an upcoming test tomorrow. For question 2, I attempt to use the Kinetic Work Energy theorem to solve for the Work done by friction, but I don't get a correct answer. As you can see, I attempted certain things...

How would one find the reference frame in which an object [which undergoes a perfectly inelastic collision with a second object] experiences no change in its kinetic energy?

Homework Statement (a) What is the minimum kinetic energy in electron volts that an electron must have to be able to ionize a hydrogen atom (that is, remove the electron from being bound to the proton)? Answer: 13.6 eV (b) If electrons of energy 12.8 eV are incident on a gas of hydrogen...

Hi there, I've been given a statement in which I need to find out where Kinetic Energy goes when a moving lorry breaks to avoid a collision?There are no equations given. Only information needed to complete the question.I have tried looking around the internet to see what the possible answer...

When calculating the total kinetic energy do i have to take into account the rotational kinetic energy of the wheels?

Would there be any way to get the energy from the rotation of a planet, which is an Earth like planet in material, sized like Jupiter, and seems to have a 24 hr day. I am just starting to get into real Physics, So I am not even sure where to start getting the numbers to work with, and I would...

Homework Statement Not a homework or coursework question, but given the simplicity of the problem I feel that this is an appropriate subforum. Consider a person spinning a rock on a string above their head at a constant angular velocity, walking away from the observer at a constant linear...

I would like to know if kinetics energy of a disk with radius 'r', mass 'm' which turn around itself at Wb (relative rotation) and which turn around blue axis at distance 'd' is : 1/2md²Wa²+1/2mr²(Wa−Wb)² ? With Wa > Wb Look at image please.

Homework Statement Hello, first year engineering student here :)https://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-xpf1/v/t35.0-12/10744040_871781156179440_107104578_o.jpg?oh=73c4261941e7ef6b7c682558c0925a63&oe=544F5CA4&__gda__=1414428985_0415c28b8b2e194bf0b57f065267fe49 [/B] The question is...

Homework Statement When a 7 3 Li nucleus is bombarded with protons α particles emerge.Calculate the kinetic energy of the alpha particle assuming the kinetic energy of the bombarding proton to be negligible. Given M (7 3 Li)=7.016004a.m.u. M (p)=1.007826a.m.u and M (α)=4.002603a.m.u. Homework...

1. The problem statement & given/known data A neutron star is a collection of neutrons bound together by their mutual gravitation. The density of such a star is comparable to that of an atomic nucleus (10^17 kg/m^3). a) Assuming the neutron star to be spherical in shape and of uniform mass...

Why would the coefficient of kinetic friction be larger for an inclined plane versus a horizontal plane? Would it be related to the material? I thought initially it was something to do with the force of gravity… but apparently that's not it :( Thanks so much in advance!

Thanks everyone for your help.

While I am familiar with the derivation of the relationship between mean translational kinetic energy, ##<E_k>##, and temperature, ##T##, for an ideal gas (namely ##<E_k> = \frac{3}{2}k_B T##); I fail to see how we can establish such a relationship for solids, liquids, and even real gases. Could...

Homework Statement A 2000kg car is moving at 50km/h. What is the force required to stop it? Homework Equations KE=1/2m(v^2) p=m*v The Attempt at a Solution 1/2(2000kg)*(50km/h)^2 = 1000kg*2500km^2/h^2 = 2,500,000 km^2/h^2 converting from hours to seconds and km to m (to get joules)...

Homework Statement The 40 kg crate shown in the Figure below rests on a horizontal plane for which the coefficient of kinetic friction is mk = 0.3. If the crate is subjected to a 350 N towing force as shown, determine the speed of the crate 3 seconds after starting from rest. + given angle of...

I know that momentum is conserved when no "net" external forces such as Friction, Gravity, and air resistnace normal force; However, during inelastic collisions it says kinetic energy is not conserved because of external forces as well. 1. Are the external forces different for mechanical energy...

Homework Statement An asteroid of mass m = 2.6 × 10^6 kg approaches the Earth. When it is exactly 3 Earth radii away from the Earth's centre its speed relative to the Earth's centre is u = 8.7 × 10^3 m s–1. The asteroid subsequently falls down to the Earth's surface. You may assume that the...

Homework Statement An asteroid of mass m = 2.6 × 10^6 kg approaches the Earth. When it is exactly 3 Earth radii away from the Earth's centre its speed relative to the Earth's centre is u = 8.7 × 10^3 m s–1. The asteroid subsequently falls down to the Earth's surface. You may assume that the...

Homework Statement The nuclear masses of parent and daughter nuclei are Mp= 226.025 amu and Md=222.017 amu.Mass of alpha particle is Mα=4.002amu.Find qvalue and kinetic energy of alpha particle emitted for the alpha decay. Homework Equations Q=(Mp -Md-Mα)amu...1 Assuming nucleus to be at rest...

Please help! I have a test tomorrow. 1. Homework Statement A car with a weight of 15,000 N moves horizontally at 30 m/s. a) What is the car's KE? b) What will be the magnitude friction force to stop the car over a 60m distance? Homework Equations F=ma KE=1/2*m*v2 The Attempt at a Solution a)...

Homework Statement A person pulls a box (m=10 kg) horizontally with +2m/s2 acceleration by applying 45 N force. The displacement of the box is 8 meters from initial position. a) How much work is done by applied force? b) How much work is done by kinetic frictional force? Homework Equations Wf...