el uso sistemático de ejercicios para promover la aptitud física y la fuerza.
Answer:
A
Explanation:
they are atoms of the same element that have the same number of protons but different number of neutrons.
Answer:

Explanation:
The vertical component of the initial velocities are

If we ignore air resistance, and let g = -9.81 m/s2. The the time it takes for the projectiles to travel, vertically speaking, can be calculated in the following motion equation




So the ratio of the times of the flights is
