Answer:
Explanation:
Since the block is at rest in an elevated position, we can assume that it only has potential energy.
U=mgh is the formula for potential energy where U=potential energy, m= mass, g=acceleration due to gravity, and h=height.
Plug in known variables....
U=4kg*9.8m/s^2*20m
U=784 joules of potential energy or letter A.
The missing part of the incomplete question is given below:
Which important step of scientific design is Shameka conducting?
repetition
replication
verification of results
using controlled variables
Answer:
Verification of results
Explanation:
The way toward gathering five examples of water from various sources is conveyed to confirm the outcome. By gathering water from five distinct areas of a similar source the analyst can genuinely find out the nature of the water in her region of remain.
On the off chance that after examples are tried it is found the water isn't sound, the outcomes would be acknowledged as it has been appropriately checked and a proper move would be made.
Thus, the correct answer is - verification of results
Answer:
A) If the paintball stops completely the magnitude of the change in the paintball’s momentum is 
B) If the paintball bounces off its target and afterward moves in the opposite direction with the same speed, the change in the paintball’s momentum is 
C) A paintball bouncing off your skin in the opposite direction with the same speed hurts more than a paintball exploding upon your skin because of the strength exerted is twice than if it explodes.
Explanation:
Hi
A) We use the formula of momentum
, so we have 
B) We use the same formula above, then due we have a change of direction at the same speed, therefore the change in the momentum is the double so
.
C) The average strength of the force an object exerts during impact is determined by the amount the object’s momentum changes. therefore
, as we don't have any data about the impact time but we know momentum is twice, time does no matter and strength is twice too.
The body systems that help cells get the energy they need are the digestive system and circulatory system. The first system is the digestive system because when you eat food, your body breaks it down using the stomach and other different parts of the digestive system. The next one is the circulatory system because your blood carries the nutrients you acquired from food you digested to the cells throughout your body.
the answer is True you can convert matter and energy