Answer:
28.3 kg
Explanation:
Assuming the ground is level, the normal force equals the weight.
N = mg
277 N = m × 9.8 m/s²
m = 28.3 kg
All of these things were seen in formal experiments by the 19th century. But some of them are easy to see in your own home. It's obvious that light can reflect - you just have to look in a mirror. Light bounces off the mirror and goes into your eye so you can see yourself. It's also obvious that light can refract: All you have to do is put a spoon in a large glass of water and watch how the spoon appears to bend.
That happens because the light is bending as it moves between air and water. Both of these things can be seen even more clearly in a laboratory using beams of light or lasers.
The sign associated with the average velocity of the object is negative.
<h3>
Average velocity of the object</h3>
The average velocity of the object is calculated as follows;
Average velocity = (v1 + v2)/2
v1 = -20/30 = -0.667 m/s
v2 = 20/50 = 0.4 m/s
Average velocity = (-0.667 + 0.4)/2
Average velocity = -0.134 m/s
Thus, the sign associated with the average velocity of the object is negative.
Learn more about average velocity here: brainly.com/question/6504879
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To solve this problem it is necessary to apply the concepts related to the Heisenberg's uncertainty principle. Under this principle we understand the relationship that the minimum range of error in position (x) times the minimum range of error in momentum (p) is, at a minimum, about equal to the Planck constant, mathematically that is,

Replacing with our values we have,


Therefore the least uncertainty in any simultaneous measurement of the momentum component px of this electron is 
Answer:
square root of 2gh
Explanation:
gh=(1/2)(v^2)
dividing both sides by 1/2, we have
2gh=v^2
therefore;
v=square root of 2gh