We know that potential energy is simply energy due to
position which has the formula:
PE = mass * gravity * height
We know that mass * gravity is weight, therefore:
PE = weight * height
27500 J = weight * 42 m
<span>weight = 654.76 Newtons</span>
Answer:
The polar coordinate of
is
.
Explanation:
Given a point in rectangular form, that is
, its polar form is defined by:
(1)
Where:
- Norm, measured in meters.
- Direction, measured in sexagesimal degrees.
The norm of the point is determined by Pythagorean Theorem:
(2)
And direction is calculated by following trigonometric relation:
(3)
If we know that
and
, then the components of coordinates in polar form is:
![r = \sqrt{(-3.50\,m)^{2}+(-2.50\,m)^{2}}](https://tex.z-dn.net/?f=r%20%3D%20%5Csqrt%7B%28-3.50%5C%2Cm%29%5E%7B2%7D%2B%28-2.50%5C%2Cm%29%5E%7B2%7D%7D)
![r \approx 4.301\,m](https://tex.z-dn.net/?f=r%20%5Capprox%204.301%5C%2Cm)
Since
and
, direction is located at 3rd Quadrant. Given that tangent function has a period of 180º, we find direction by using this formula:
![\theta = 180^{\circ}+\tan^{-1} \left(\frac{-2.50\,m}{-3.50\,m} \right)](https://tex.z-dn.net/?f=%5Ctheta%20%3D%20180%5E%7B%5Ccirc%7D%2B%5Ctan%5E%7B-1%7D%20%5Cleft%28%5Cfrac%7B-2.50%5C%2Cm%7D%7B-3.50%5C%2Cm%7D%20%5Cright%29)
![\theta \approx 215.538^{\circ}](https://tex.z-dn.net/?f=%5Ctheta%20%5Capprox%20215.538%5E%7B%5Ccirc%7D)
The polar coordinate of
is
.
Let say the two train cars are of masses
and ![m_2](https://tex.z-dn.net/?f=m_2)
now if the speed of two cars are
and ![v_2](https://tex.z-dn.net/?f=v_2)
then we can say that the momentum of two cars before they collide is given by
![P = m_1v_1 - m_2v_2](https://tex.z-dn.net/?f=P%20%3D%20m_1v_1%20-%20m_2v_2)
here two cars are moving in opposite direction so we can say that the net momentum is subtraction of two cars momentum.
Now since in these two car motion there is no external force on them while they collide
So the momentum of two cars are always conserved.
hence we can say that the final momentum of two cars will be same after collision as it is before collision
![P = m_1v_1 - m_2v_2](https://tex.z-dn.net/?f=P%20%3D%20m_1v_1%20-%20m_2v_2)
The directions of the vectors for velocity and acceleration are in the opposite directions.
- The velocity vector is always in the direction of motion of the object. So, the direction of velocity is in the right from our point of view.
- When there is a positive acceleration in the object the acceleration vector is in the direction of motion of the object. When there is a negative acceleration in the object the acceleration vector is in the opposite direction of motion of the object. So, the direction of velocity is in the left from our point of view.
Velocity vector is the rate of change of position of an object. Acceleration vector is the rate of change of velocity of an object.
Therefore, the directions of the vectors for velocity and acceleration are in the opposite directions.
To know more about velocity and acceleration vectors
brainly.com/question/13492374
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