It started that the present is the key to the past. The process that we see in operation today are the same ones that have operated in the geologic past.
While skydiving, its not just freely falling under Earth's gravity. Additional force called drag acts against the gravity which slows down the rate of fall. Drag is caused by the air molecules which pushes against the body as it falls through them. This is actually a significant amount of force which slows down the rate of fall of the body. Drag depends on the contact surface area and weight. More the surface area in contact, more would be the drag. The sitting position of the skydiver would experience less drag than the chest down position because of the less contact surface area of the body with the air molecules while in the former case. No two persons have identical body shape and weight. Hence, the rate of fall can be made nearly equal but not exactly equal. This is would be possible when they are having same body position.
Answer: 3 m/s
Explanation:
We can solve the problem by using the law of conservation of momentum: during the collision between the two balls, the total momentum of the system before the collision and after the collision must be conserved:
The total momentum before the collision is given only by the cue ball, since the solid ball is initially at rest, therefore
So, the final total momentum will also be
And the total momentum after the collision is given only by the solid ball, since the cue ball is now at rest, therefore:
from which we find the velocity of the solid ball
Answer:
Yes such a frame exists: a free-fall (free-float frame) frame. This frame of reference is subject only to gravity and no forces such as electromagnetic forces or nuclear forces.
