Ratio of the velocities of two atoms, based on kinetic energy

AI Thread Summary
The discussion centers on calculating the ratio of velocities between a helium atom and an oxygen atom, given that they possess the same kinetic energy. The oxygen atom is four times more massive than the helium atom. By applying the kinetic energy equation, the user rearranges the terms to isolate the velocity ratio. The final calculation shows that the ratio of the speeds is vHe/vO = 2, indicating that the helium atom moves twice as fast as the oxygen atom. This conclusion is reached through basic algebraic manipulation of the kinetic energy formula.
buttermellow
Messages
8
Reaction score
0

Homework Statement



An oxygen atom is four times as massive as a helium atom. In an experiment, a helium atom and an oxygen atom have the same kinetic energy. What is the ratio vHe /vO of their speeds?



Homework Equations


K=.5mv2


The Attempt at a Solution



.5mHe(vHe)2=.5(4mHe)(vO)2

I'm not sure what to do with that though, how to solve for the ratio.
 
Physics news on Phys.org
Have you learned basic algebraic manipulation? You just have to rearrange the equation so as to get the ratio V(he)/V(o) on one side. eg. 5a = 3b, a/b = ?
 
Oh my, I was making that much harder than it needed to be.

What I got:
.5mHe(vHe)2=2mHe(vO)2
mHe cancels to give (vHe)2=4(vO)2
(vHe)2/(vO)2=4
vHe/vO=\sqrt{}4=2
 
Last edited:
Thread 'Variable mass system : water sprayed into a moving container'

Thread 'Variable mass system : water sprayed into a moving container'

Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
View full post »

Similar threads

Comparing Velocities through Kinetic Energy
Replies
4
Views
1K
Do you graph the energy levels of a ##1s^1## atom the same as a ##1s^2## atom?
Replies
12
Views
854
The Total Energy of the Hydrogen Atom's Electron
Replies
2
Views
1K
Kinetic energy of recoil atom in the photoelectric effect
Replies
1
Views
3K
Minimum Kinetic energy of the hydrogen atom
Replies
22
Views
3K
Resistance force changing the velocity of an object
Replies
8
Views
1K
Internal energy of a gas and kinetic energy, "typical velocity"
Replies
5
Views
803
Conservation of Momentum Problem - Mechanical and Kinetic Energies
Replies
2
Views
956
Potential/Kinetic Energy of Particles in Harmonic Oscillator
Replies
2
Views
2K
Calculating RMS Speed of Helium & Oxygen Gas at 260K
Replies
6
Views
5K

Hot Threads

Recent Insights

Back
Top