The average velocity is -4.17 m/s
Explanation:
The average velocity of a body is given by:
where
d is the displacement of the body
t is the time elapsed
For the student in this problem, we have:
Initial position:
Final position:
So the displacement is
The time elapsed is
t = 60 s
Therefore, the average velocity is
Where the negative sign means the student is moving towards the origin.
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Answer:
Explanation:
If we make an analysis of the net force of the rock that was thrown upwards, we will have the following:
(1)
Where:
is the force with which the rock was thrown
is the weight of the rock
Being the weight the relation between the mass of the rock and the acceleration due gravity
:
(2)
(3)
Substituting (3) in (1):
(4)
(5) This is the net Force on the rock
On the other hand, we know this force is equal to the multiplication of the mass with the acceleration, according to Newton's 2nd Law:
(6)
Finding the acceleration :
(7)
(8)
Finally: