Answer:
is the mass of librarian.
Explanation:
Given:
- mass of the system,

- velocity of librarian relative to the ground,

- velocity of the cart relative to the ground,

N<u>ow using the principle of elastic collision:</u>
Net momentum of the system is zero.


is the mass of librarian.
It stops cause of gravitaional pull
Answer:
The correct answer is A
Explanation:
The question requires as well the attached image, so please see that below.
Coulomb's Law.
The electrical force can be understood by remembering Coulomb's Law, that describes the electrostatic force between two charged particles. If the particles have charges
and
, are separated by a distance r and are at rest relative to each other, then its electrostatic force magnitude on particle 1 due particle 2 is given by:

Thus if we decrease the distance by half we have

So we get

Replacing we get

We can then multiply both numerator and denominator by 4 to get

So we have

Thus if we decrease the distance by half we get four times the force.
Then we can replace the second condition

So we get

which give us

Thus doubling one of the charges doubles the force.
So the answer is A.
Answer:
C. An inital volocity that is faster than the final volocity
Explanation:
.
<span>3. The attempt at a solution So basically what I did was divided into components. x: (3)(2000) = (3000)*v_x y: (v_vw)*(10000) = (3000)*v_y v_x, v_y is the velocity (after collision) in the x and y direction, respectively, of both cars stuck together (since it is an inelastic collision). v_vw is the initial velocity of the Volkswagen. Now what I did was that the angle is 35 degrees north of east. So basically made a triangle and figured that tan(35) = (v_y)/(v_x). This means (v_x)*(tan35) = v_y. Then, I simplified the component equations to get: x: 2 = v_x y: v_vw = 3*v_y Then plugging in for v_y, I got: v_vw = 3(2)(tan35) = 4.2 m/s as the velocity of the volkswagen. However, the answer key says 8.6 m/s. Could someone please help me out? Thanks Phys.org - latest science and technology news stories on Phys.org • Game over? Computer beats human champ in ancient Chinese game • Simplifying solar cells with a new mix of materials • Imaged 'jets' reveal cerium's post-shock inner strength Oct 24, 2012 #2 ehild Homework Helper Gold Member What directions you call x and y?
Reference https://www.physicsforums.com/threads/2d-momentum-problem.646613/</span>