A pendulum is an object hung from a fixed point that swings back and forth under the action of gravity. In the example of the playground swing, the swing is supported by chains that are attached to fixed points at the top of the swing set. When the swing is raised and released, it will move freely back and forth due to the force of gravity on it. The swing continues moving back and forth without any extra outside help until friction (between the air and the swing and between the chains and the attachment points) slows it down and eventually stops it.
A). Archaea Hope it helps you
In order to design an experiment, you need a hypothesis about the scientific question you are trying to answer.
Answer:
in the direction of motion of Jacob
Explanation:
Given:
mass of Jacob, 
velocity of Jacob, 
mass of Ethan, 
velocity of Ethan, 
Now using the conservation of linear momentum for the case:
(When the two masses in motion combine to form one after the collision then they will move together in the direction of the greater momentum.)


in the direction of motion of Jacob as it was assumed to be positive.
Sorry but you tell me not to ask for help or answers but you want them yourself