Which is the 2nd closest star to earth??
2 answers:
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Answer: 815.51 m
Explanation:
This situation is related to projectile motion or parabolic motion, in which the initial velocity of the bullet has only y-component, since it was fired straight up. In addition, we are dealing with constant acceleration (due gravity), therefore the following equations will be useful to solve this problem:
(1)
(2)
Where:
is the final velocity of the bullet
is the initial velocity of the bullet
is the acceleration due gravity, always directed downwards
is the time
is the vertical position of the bullet at
Let's begin by finding from (1):
(3)
(4)
Now we have to substitute (4) in (2):
(5)
Isolating :
This is the displacement of the bullet after 6.9 s
1) Magnitude of the net force: 20.8 N
2) Angle: clockwise from positive x-direction
Explanation:
1)
First of all, we need to find the components of the resultant force along the horizontal and vertical direction.
We observe that there are two forces acting along the horizontal direction:
We notice that they act in opposite directions, so the net force in the horizontal direction is the difference between these two forces:
(to the right)
Instead, there is only one force acting in the vertical direction, so the net force in the vertical direction is:
(downward)
Therefore, the magnitude of the net force can be found by using Pythagorean's theorem:
2)
Now we have to find the angle of the resultant net force. We can do it by using the following equation:
where
is the angle, measured as clockwise from the positive x-direction (because the vertical net force is downward)
is the vertical net force
is the horizontal net force
Solving, we find:
And so the angle is
In a direction down with respect to the right.
Learn more about forces:
About addition of vectors:
#LearnwithBrainly
a) Making h as the shorter cathetus, we have,
We proceed to calculate the work done by gravity
b) It's necessary to calculate the Kinetic Energy, we use the equation of KE,
c) By work energy theorem
d) we calculate net work through the law of conservation