a0.155 kg arrow is shot from ground level, upward at 31.4 m/s. what is its kinetic energy (ke) when it is 30.0 m above the groun
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Answer:
<h3>The answer is 0.54 g/cm³</h3>Explanation:
The density of a substance can be found by using the formula
From the question we have
We have the final answer as
<h3>0.54 g/cm³</h3>Hope this helps you
Answer:
58.27 N
Explanation:
the data we have is:
mass:
coefficient of friction:
and we also know the acceleration of gravity is
We need to do an analysis of horizontal and vertical forces acting on the object:
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Vertically the forces acting on the object:
- Normal force
(acting up from the object)
- weight:
(acting down from)
so the sum of forces in the vertical axis "y" are:
from Newton's second Law we know that , so:
and since the object is not accelerating in the vertical direction (the movement is only horizontal) , and:
-----------
now let's analyze the horizontal forces
- frictional force:
and since
-->
- force to move the object:
and the two forces just mentioned must be opposite, thus the sum of forces in the "x" axis is:
and we are told that the crate moves at a steady speed, thus there is no acceleration:
and we get:
substituting known values: