Answer:
Part A W= 2772J
Part B = -2.772J
Explanation:
Work = force × distance
Part A when you move from lower to upper level
= mgh
= 63× 4.4×10
=2772J
=2.772KJ
Part B
When you move from upper to lower
The acceleration due to gravity becomes negative -10m/s^2
Therefore Work =-2772KJ
Work = -2.772KJ
Answer:
Time dilation. Time dilation, in the theory of special relativity, the “slowing down” of a clock as determined by an observer who is in relative motion with respect to that clock.The world's most accurate clock has neatly shown how right Albert Einstein was 100 years ago, when he proposed that time is a relative concept and the higher you live above sea level the faster you should age. Einstein's theory of relativity states that time and space are not as constant as everyday life would suggest.The theory of relativity usually encompasses two interrelated theories by Albert Einstein: special relativity and general relativity. Special relativity applies to all physical phenomena in the absence of gravity. General relativity explains the law of gravitation and its relation to other forces of nature.
Explanation:
Answer:
D. When the box is placed in an elevator accelerating upward
Explanation:
Looking at the answer choices, we know that we want to find out how the normal force varies with the motion of the box. In all cases listed in the answer choices, there are two forces acting on the box: the normal force and the force of gravity. These two act in opposite directions: the normal force, N, in the upward direction and gravity, mg, in the downward direction. Taking the upward direction to be positive, we can express the net force on the box as N - mg.
From Newton's Second Law, this is also equal to ma, where a is the acceleration of the box (again with the upward direction being positive). For answer choices (A) and (B), the net acceleration of the box is zero, so N = mg. We can see how the acceleration of the elevator (and, hence, of the box) affects the normal force. The larger the acceleration (in the positive, i.e., upward, direction), the larger the normal force is to preserve the equality: N - mg = ma, N = ma+ mg. Answer choice (D), in which the elevator is accelerating upward, results in the greatest normal force, since in that case the magnitude of the normal force is greater than gravity by the amount ma.
F = m · a (Newton's 2nd law of motion)
F = (5 kg) · (4 m/s )
<em>F = 20 Newtons</em>
I think it depend on the curvature of the reflective surface, right? if it is an Mirror, then the angles should mirror itself.
