No additional force is required because it's already going downhill
Answer:
The magnitude of change in momentum is (2mv).
Explanation:
The momentum of an object is given by the product of mass and velocity with which it is moving.
Let the mass of ball is m. A tennis player smashes a ball of mass m horizontally at a vertical wall. The ball rebounds at the same speed v with which it struck the wall.
Initial speed of the ball is v and final speed, when it rebounds, is (-v). The change in momentum is given by :
p = final momentum - initial momentum

So, the magnitude of change in momentum is (2mv).
Answer:
Forces affect how objects move. They may cause motion; they may also slow, stop, or change the direction of motion of an object that is already moving. Since force cause changes in the speed or direction of an object, we can say that forces cause changes in velocity.
You are in an early universe.
In the study of the evolution of the universe, it has been determined before Plank time (before the big bang and right after it), the early universe had the following characteristics:
- There was only one single force acting over all that existed.
- The early universe was very hot and dense because all matter had contracted before the big bang.
- Space and time were wrapped.
These characteristics match the ones described, based on this, we can conclude you are in an early universe.
Learn more about universe in: brainly.com/question/9724831