Open study

is now brainly

With Brainly you can:

  • Get homework help from millions of students and moderators
  • Learn how to solve problems with step-by-step explanations
  • Share your knowledge and earn points by helping other students
  • Learn anywhere, anytime with the Brainly app!

A community for students.

I have a doubt in the answer key to the problem on law of conservation of momentum. The question: A girl of mass 50 kg jumps out of a rowing boat of mass 300 kg on to the bank with a horizontal velocity of 3 m/s. With what velocity does the boat move backwards? Answer key says: m1(mass of girl) = 50 kg m2(mass of boat) = 300kg v1(velocity of girl) = 3 m/s v2 = ? m1v1 + m2v2 = 0 How can the momentum of the whole system after the girl jumps out of the boat be 0? The boat will have some momentum right?

Physics
See more answers at brainly.com
At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non provident, similique sunt in culpa qui officia deserunt mollitia animi, id est laborum et dolorum fuga. Et harum quidem rerum facilis est et expedita distinctio. Nam libero tempore, cum soluta nobis est eligendi optio cumque nihil impedit quo minus id quod maxime placeat facere possimus, omnis voluptas assumenda est, omnis dolor repellendus. Itaque earum rerum hic tenetur a sapiente delectus, ut aut reiciendis voluptatibus maiores alias consequatur aut perferendis doloribus asperiores repellat.

Get this expert

answer on brainly

SEE EXPERT ANSWER

Get your free account and access expert answers to this and thousands of other questions

Right. The boat must have some change in velocity, since the momentum must be conserved and the momentum of the girl changed.
it is just same as recoil velocity of Gun..
but even in recoiling of gun, how can the final momentum be 0?

Not the answer you are looking for?

Search for more explanations.

Ask your own question

Other answers:

v = - Mv/m = -50*3/300 = -0.5m/s
Yes, I know the answer but I can't understand how total momentum is 0.
Law of conservation of momentum..says that momentum is conserved
Do..u knw abt Rocket propulsion
Momenta are vectors.
If you have two vectors in opposite directions, they can cancel eachother out.
even though the mass gets reduced..the momentum is conserved
even if they are different?
The girl's momentum is in one direction and the boat's in another direction.
yup..@Xishem has a point there
I mean do they cancel each other even if the magnitudes are different?
The magnitudes aren't different.
Remember, momentum is a function of both mass and velocity.
If one object with 1kg mass and 10m/s velocity is moving right and another of 10kg mass and 1m/s velocity is moving left, the total momentum is zero.
So mass*velocity of the bullet or girl will always be equal to mass*velocity of gun or boat?
Yes, assuming you are in a closed system. Which you are.
What is a closed system?
Please help I have a test coming up soon.
A closed system is a physical system which doesn't exchange any matter in or out of itself and which isn't affected by outside forces.
It basically just means that you are only considering the two objects and not nonconservative forces like friction which would change the overall momentum. (This case is frictionless, but that's one case where momentum won't be conserved).
Thanks I got it now.
This doesn't happen in the case of a collision right?
Momentum is not conserved in an inelastic collision. Momentum is conserved in an elastic collision.
In the real world, momentum is never conserved in collisions. When two pool balls hit eachother for instance, they release some sound upon impact -- this is lost energy. They are also always under the effect of friction from the table.
Thanks.

Not the answer you are looking for?

Search for more explanations.

Ask your own question