Answer:
Explanation:
A closed system is a system where exists energy interactions with surroundings, but not mass interactions. If we neglect any energy interactions from boundary work, heat, electricity, magnetism and nuclear phenomena and assume that process occurs at steady state and all effects from non-conservative forces can be neglected, then the equation of energy conservation is reduce to this form:
(1)
Where:
- Change in kinetic energy of the system, measured in joules.
- Change in gravitational potential energy of the system, measured in joules.
If we know that 
and 
, then we get the following equation:
(2)
Where 
and 
stands for initial and final states of each energy component.
Hence, the right answer is
The law of conservation of momentum basically means that energy is always conserved and never lost when a collision happens.
Using the formula p=mv ...
Player A would have a momentum of 220 N•S
Player B would have a momentum of 0 because he is not moving
After the collision, the total momentum is still 220 N•S because energy is never lost, but now player A is at 0 and player B took his momentum. Think about it this way, if you bumped into something that wasn’t moving, it would fall and you most likely wouldn’t keep moving.
Elastic collisions are where the objects bounce each other and in inelastic collisions they stick together. I don’t watch much football but if you do this should make sense.
If the players fall down together (they tackle each other and fall? I think) it should be inelastic.
Sorry if this was long and confusing but I really hope this helps! ☺️
Answer: Yes
Air serves as a propagation medium.
Explanation:
Propagation of sound wave require a medium for transmission. Sound is produced by vibrating objects, The matter or substance through which sound is transmitted is called a medium. It can be solid, liquid or gas. Therefore to propagate sounds (human voice) from one end of a lecture hall to the other we need a propagation medium which is air. Air serves as a propagation medium.
"When we do experiments it's a good idea to do multiple trials, that is, do the same experiment lots of times. When we do multiple trials of the same experiment, we can make sure that our results are consistent and not altered by random events. Multiple trials can be done at one time."
