Read about kinetic energy | 240 Discussions | Page 1

Hi all, I've read so many times that "temperature is a measure of the average kinetic energy of the molecules in a substance," or sometimes "particles" to encompass atoms and ions too. But how big can "molecules/particles" be before their kinetic energy is no longer relevant to temperature? If...

(Note: I had this question posted at the intermediate level of difficulty for 11 days, but got only one, cryptic (to me) response that was rather quickly removed. So, I figured perhaps it's actually an advanced question, requiring more than a cursory understanding.) Assuming they've had an...

So far I found the answer for a and b, but when I attempted to do the other ones I was completely lost. A.) P= MV M = 25g = .025kg V = 18 .025 * 18 = .45kg*m/s B.) KE= 1/2 mv^2 1/2 (.025)(18)^2 4.05 J

Homework Statement:: Consider an electron trapped in a one-dimensional finite well of width L. What is the minimum possible kinetic energy of the electron? A) 0 B) Between 0 and h^2/8mL^2 C) ≈h^2/8mL^2, but it is not possible to find the exact value because of the uncertainty principle D)...

I got acceleration by dividing force by m then replaced a by dv/dt and then integrated it to get velocity as a fxn of time and hence got kinetic energy but problem is my ans does not match with any option can someone please compare their ans

I'm programming a game in which I'd like to simulate the real world physics of an attack using primarily medieval style weapons. Think dwarf fortress, but rather than assigning damage numbers we're calculating force or kinetic energy. Getting that much is easy enough since I can find the mass of...

I drew a diagram for the a) part The person is h meters high So GPE= 100 x 9.8x h GPE= 980h j KE = 980h when the person hits the see saw KE=1/2mv² 980h=0.5 x 5 x v² Now it v²=u²+2as For the brick going up to 10m v = 0 u=? a=-9.8ms-² s=10m u²=2 x 9.8 x 10 u=14m/s We can assume that u=14m/s is...

So first I tried to use KE=1/2 x m x v^2 but then realised I didn’t have the velocity and I can’t figure out a way to obtain it. I then tried to work out the energy using a different equation, W= q x v but that left me with 1.28x10^-14 J which seemed too small. I also then have to calculate the...

So the equation for work is W = F * s F = m * a, so W = m * a * s Transferring this to units of measurement gives us: J = kg * m * s-2 * m Or simplified: J = kg * m2 * s-2 Transferring back to units of quantity: W = m * v2 How can that be correct? Obviously Ekin = 1/2 * m * v2. Where did that...

Imagine a 400-meter-long pipe with a 1600-meter diameter, floating in inter-planetary space. It is spinning at 0.5 gravity along its major axis and there are no secondary-axes spins. We need to increase rotation to 0.85 g. Its density is a uniform 2.3 kg/m³ and it weighs 49,120,056 kg. Thanks to...

1. Determine the velocity of the ball when it is 30degrees from the horizontal: U1 = mgh = mg(0.8m) U2 = mgh = mg(0.4+0.4cos(30)) = mg(.74641) ΔU = U2 - U1 = mg(.74641 - .8) = mg(-0.051433) T1 =0 T2 = 0.5mv^2 ΔT = T2 - T1 = 0.5mv^2 ΔU = ΔT mg(-0.051433) = 0.5mv^2 ====> v = 1.025394 2. Use...

Homework Statement In two rockets, one of which moves and the other is at rest, the motors are connected for a short time. During their operation they throw the same mass of gas (small in comparison with the mass of the rocket) at the same speed with respect to the rockets. The kinetic energy...

Homework Statement The system is released from rest with no slack in the cable and with the spring stretched 225 mm. Determine the distance s traveled by the 3.2-kg cart before it comes to rest (a) if m approaches zero and (b) if m = 2.5 kg. Assume no mechanical interference and no friction...

Homework Statement A ball of mass m=0.300 kg is connected by a strong massless rod of length L = 0.800 m to a pivot and held in place with the rod vertical. A wind exerts constant force F to the right on the ball as shown below. The ball is released from rest. The wind makes it swing up to...

So I found the linear velocity by using the circumference of the earth which I found to be 2pi(637800= 40014155.89meters. Then the time of one full rotation was 1436.97 minutes, which I then converted to 86164.2 seconds. giving me the linear velocity to be 465.0905584 meters/second. I know that...

Homework Statement A rocket burns out at an altitude h above the Earth's surface. Its speed v0 at burnout exceeds the escape speed vesc appropriate to the burnout altitude. Show that the speed v of the rocket very far from the Earth is given by v=(v02-v2esc)1/2 Homework Equations KEf-KEi=Ui-Uf...

Homework Statement "A spring with a spring constant "k" is compressed 10 cm from equilibrium. A ball of mass 100 g is at rest next to it. The spring then decompresses quickly back to its equilibrium position causing the ball to shoot forward. If the spring constant is 500 N/m, what is the...

Homework Statement Rank the four objects (1kg solid sphere, 1kg hollow sphere, 2kg solid sphere and 1kg hoop) from fastest down the ramp to slowest. (Please see the attached screenshot for more details.) Homework Equations KE_rot = 1/2Iw^2 (where omega = w) The Attempt at a Solution Since we...

Dear Sirs, If I take this explanation as being true "The heat is generated on the microscale when the conduction electrons transfer energy to the conductor's atoms by way of collisions." So a "current" must have a quantum of kinetic energy going into the conductor (resistive element) and a...

Homework Statement Please look at the problem attached as a screenshot. Homework Equations Assuming frictionless, Ei = Ef, which means objects that are the same will end up in the same heights (so we can group A&C, B&D, and E&F). For A&C and E&F, mgh = KE_rot + KE_trans For B&D, it is mgh...

Homework Statement Please see the attached file. Homework Equations Ei = Ef The Attempt at a Solution I don't have an answer key provided, but I'd really like to verify that I'm right (or if I'm wrong, why). I think ti'd be (c) because assuming that due to inertia, B will continue going...

Homework Statement Please look at the attached screenshot. Homework Equations Assuming the ramp is frictionless, Ei = Ef and thus mgh = KE ( = 1/2mv^2, which isn't really necessary here) The Attempt at a Solution I'm okay with all other examples except for A and C. From the answer template...

Homework Statement There is a train of length d and speed v. It is heading towards a hill with height h and length of each side l. What velocity requirement must be met so that the train can go up and down the hill? Homework Equations Ek=m⋅v2/2 Ep=m⋅g⋅h The Attempt at a Solution I'm basically...

Homework Statement What is the kinetic energy of a particle in 2mol of nitrogen gas at atmospheric pressure that is within a volume of 100m^3? a. 1.27X10^-17J b. 3X10^5J c. 6.8X10^-16J d. 2.97X10^7 e. 9.9X10^-14J Homework Equations PV=nRT n=Numberof particles/Na Na=6.02x10^23 R=8.13 J/Mol...

Homework Statement Please look at the attached screenshot. This problem is really confusing for me and I can't seem to make much sense out of it. Homework Equations Ei = Ef The Attempt at a Solution As you can see, I did get (a). (The other checkmarks, I guessed — there were only two...

Homework Statement Movers must push a piano onto a truck, the bed of which is a height 1.35 m above the ground. To do this they will use a frictionless ramp. If the piano has a mass of 1806.0 kg and the movers push it up the slope at a constant velocity, how much work do they need to do on it...

Homework Statement A proton strikes a stationary alpha particle (4He nucleus) head-on. Assuming the collision is completely elastic, what fraction of the proton’s kinetic energy is transferred to the alpha particle? Homework Equations Pi = Pf Ki = Kf The Attempt at a Solution Tried finding...

Why kinetic energy is ½ m v2? Why it is different from Einstein’s equation for Energy E= m c2?