Please i need help A 12 kg ball (ball #1) moves rightward at 4.000 m/s. It strikes a ball (ball #2) that is at rest and slows down to 1.647 m/s. Find the mass of ball #2.

this is the formula m1v1 + m2v2 = m1v1 + m2v2

If an inclined plane is 5 m long and 2 m high, what is its mechanical advantage? a. 2.5 b. 3 c. 7 d. 10

J. j. thomson’s experiment disproved the theory that an atom

The average density of the planet uranus is 1.27 103 kg/m3. the ratio of the mass of neptune to that of uranus is 1.19. the ratio of the radius of neptune to that of uranus is 0.969. find the average density of neptune.