# Recent content by PhyzicsOfHockey

1. ### Pendulum beam Problem

Homework Statement On the construction site for a new skyscraper, a uniform beam of steel is suspended from one end. If the beam swings back and forth with a period of 1.10 s, what is its length? Homework Equations T=2*pi*sqroor (L/g) The Attempt at a Solution...
2. ### Revolutions of an electron

Homework Statement A hydrogen atom exists in an excited state for typically 5.79 ns. How many revolution would an electron make in the n=2 state before decaying? Homework Equations L=m*v*Rn=h(bar)*n w=v/Rn Rn=n^2*Ao Ao=.053 nm The Attempt at a Solution Rn=4*.053=.212 nm...
3. ### A protons Min KE

Homework Statement A proton is confined in a uranium nucleus of radius 7.41 fm. Determine the proton's minimum kinetic energy K less than or equal to delta K according to the uncertainty principle if the proton is well approximated by a Gaussian wave packet confined by the nuclear diameter...
4. ### Normalization Constant A

Homework Statement The wave function of a particle is Y(x,t) = A e^-kx*e^-iwt for x greater than or equal too 0, and it is zero everywhere else. What is the numerical value of the normalization constant A for k=5.55 1/nm and w =7.19 1/ps? Homework Equations intergral Y^2=1 The...
5. ### Crazy dude jumping on a Merry-Go-Round

Energy is being lost because energy is required to make the mans speed the same speed as the merry-go-round. But thank you for your input.
6. ### Crazy dude jumping on a Merry-Go-Round

True Mentz144 but the Final KE does not equal the Initial KE. I finally figured it out. my KEi was right but I added masses when finding the new MoI not m*r^2 to the MoI of the disk.
7. ### Crazy dude jumping on a Merry-Go-Round

I guess Im not because thats still the wrong answer
8. ### Crazy dude jumping on a Merry-Go-Round

So I did KEi= .5*Imgr*Wmgr^2 + .5*Ip*Wp^2 and got 5.4524 kJ then i did KEf= .5*(M1+M2)*r^2*.5*Wf^2 and got 3.559kJ Am I even close?
9. ### Crazy dude jumping on a Merry-Go-Round

So I must include the guy running although hes not on the merry-go-round yet?
10. ### Crazy dude jumping on a Merry-Go-Round

the edge of the merry go round is moving at 11.336 m/s much fast then the man. So the merry-go-round slows down. I did conservation of momentum. Initally... Lmgr= I*w= 2310.58 Lp=I*(v/r)=623.326 Ltot= 2933.9 using this I found the angular speed of the merry-go-round fonal 2933.9/(Imgr...
11. ### Crazy dude jumping on a Merry-Go-Round

No the disk is the only thing that has KE? Maybe there is something I am just not understanding about this disk.
12. ### Crazy dude jumping on a Merry-Go-Round

Homework Statement A disk-shaped merry-go-round of radius 2.63 m and mass 155 kg rotates freely with an angular speed of 0.686 rev/s. A 59.4 kg person running tangential to the rim of the merry-go-round at 3.99 m/s jumps onto its rim and holds on. Before jumping on the merry-go-round, the...
13. ### Crane lifting crate

Homework Statement The crane shown in the drawing is lifting a 186-kg crate upward with an acceleration of 2.0 m/s2. The cable from the crate passes over a solid cylindrical pulley at the top of the boom. The pulley has a mass of 130 kg. The cable is then wound onto a hollow cylindrical drum...
14. ### Walking on a canoe, finding its mass.

I did the following... Mc=Mass canoe Mp=Mass person 4.45= distance from shore+half distance of canoe Cm=Cm (Mc+Mp)*4.45/(Mc+Mp)=Cm Cm=4.45m 4.45=3.4Mp+5.35Mc/(Mp+Mc) 4.45Mp+4.45Mc= 3.4Mp+5.35Mc 1.05Mp=.9Mc 1.1667Mp=Mc Mc= 71.983kg Is this correct? or am I not suppose to assume...
15. ### Walking on a canoe, finding its mass.

I thought of that a realized I don't know how to go about it being a center of mass problem. The only thing I really undestand is its the sum of the mass*d/total mass of the system. In this case I don't know what distances to use. Distance from the shore? Distance from the center of the...