Three balls of equal mass are fired simultaneously with equal speeds from the same height h above the ground. ball 1 is fired straight up, ball 2 is fired straight down, and ball 3 is fired horizontally. rank in order from largest to smallest the speeds of the balls, v1, v2, and v3, just before each ball hits the ground. a. v1 > v2 > v3 b. v3 > v2 > v1 c. v2 > v3 > v1 d. v1 = v2 = v3

d) v1 = v2 = v3

Explanation:

This can be answered using conservation of energy. We calculate the mechanical energy E=K+U (sum of kinetic and gravitational potential energies) at the original and final points, and impose they are equal.

At the original point we have, for the three balls:

At the final point we have, for the three balls:

Since we have , and is the same for all balls, then is the same for all balls, which means that , the final velocity, is the same for all balls.

it will be pushed away from the source of the electric field. a negative charge in a cloud induces a positive charge in the ground below the cloud.

explanation: