Answer:
6.21 m/s
Explanation:
Using work energy equation then

where d is displacement from initial to final position, v is velocity and subscripts a and b are position A and B respectively, m is mass of collar, g is acceleration due to gravity
Substituting 1 Kg for m, 0.4m for h,
as 0, 9.81 for g then

<h2>
Answer:</h2>
The event horizon is the surface of a black hole, it is the border of space-time in which the events on one side of it can not affect an observer on the other side.
That is, at this border also called "point of no return", nothing can escape (not even light) and no event that occurs within it can be seen from outside.
D.
The gravitational of a body is possessed by the body due to the virtue of its position.
The formula for gravitational potential energy is,
P.E = mgh joules
Substituting the values
196*9.8*250= 49k
D. adding one student to the team on the left
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