Total Momentum of A and B = 2mV0

  • Thread starter Thread starter kitty9035
  • Start date Start date
  • Tags Tags
    Momentum
AI Thread Summary
The total momentum of two identical objects A and B, with masses M and initial speeds of 3V0 and V0 respectively, is calculated using the formula P=mv. The momentum of object A is m(3V0) and for object B, it is m(V0). Adding these momenta gives a total momentum of m(3V0) + m(V0) = 4mV0. A participant in the discussion incorrectly suggested the total momentum as 2m + 4V0, which was identified as nonsensical. The correct expression for the total momentum is 4mV0.
kitty9035
Messages
17
Reaction score
0

Homework Statement



Two identical objects A and B of mass M move on a one-dimensional, horizontal air track. Object B initially moves to the right with speed V0. Object A initially moves to the right with speed 3V0, so that it collides with object B. Friction is negligble. Determine the total momentum of the system of the two objects. Express answers in terms of M and V0.

Homework Equations



P=mv

The Attempt at a Solution



I got an answer,but i would like verification that it's right.

I did...

Pa=(Ma)(Va) Pb=(Mb)(Vb)
Pa=m(3V0) Pb=m(V0)


Add them together...
m(3V0) + m(V0)

and get...

2m + 4v0
 
Physics news on Phys.org
kitty9035 said:
Add them together...
m(3V0) + m(V0)

and get...

2m + 4v0


That is so wrong and you know it.
 
No, I really don't. What's right?
 
Don't you notice that the expression 2m + 4v0 is non-sense? If not, I suggest you go study some algebra.
 
You're OK up to that last step. 2m + 4v0 does not make any sense. You cannot separate out the variables like that.

What's the answer to this:

3x + x = ?

If you understand that, you should see what the answer should be.
 

Thread 'Struggling to understand the concept of this question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
View full post »
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

Conservation of angular and linear momentum
Replies
8
Views
6K
Speed of a disc after a collision
Replies
2
Views
1K
Momentum dealing with decay, special relativity
Replies
6
Views
2K
Is the Book Right? Examining Conservation of Momentum
Replies
2
Views
1K
Ambiguous question on momentum and how it works...
Replies
13
Views
1K
Distance between rocket and object
Replies
30
Views
2K
Momentum of Cube: Magnitude and In-Between Speed
Replies
6
Views
1K
Angular Momentum of a Ball at Half Height
Replies
9
Views
4K
Angular momentum for a bullet and a rod attached to a ceiling
Replies
17
Views
1K
Angular Momentum Problem: Mouse walking on a rotating turntable
Replies
5
Views
1K

Hot Threads

Recent Insights

Back
Top