The equation is derived from the conservation of energy, specifically from potential energy stored at a given height in a gravitational field.
When potential energy is completely converted to kinetic energy you have:
(mv^2)/2=mgh divide both sides by the mass m
v^2/2=gh multiply both sides by 2
v^2=2gh take the square root of both sides
v=√(2gh) and working with imperial units for acceleration due to gravity, g=-32ft/s^2
v=√(-64h) but the change of h as it falls is negative h so
v=-√(64h) so if an object falls from a height of 88ft we have:
v=-√(64*84)
v=-√5376
v≈-73.32 ft/sec (to the nearest hundredth of a foot per second)
Note that this is the velocity, it is negative 73.32 ft/sec.
The question inadvertently asked for velocity and provided answers for SPEED. Velocity is a vector and has both magnitude and direction, whereas speed just has magnitude.
So its final speed is 73.32 ft/sec
So if they actually wanted velocity none of their answers is correct :P
Using the unit circle, the coordinates of 3π/4 is :
![(-\frac{\sqrt[]{2}}{2},\frac{\sqrt[]{2}}{2})](https://tex.z-dn.net/?f=%28-%5Cfrac%7B%5Csqrt%5B%5D%7B2%7D%7D%7B2%7D%2C%5Cfrac%7B%5Csqrt%5B%5D%7B2%7D%7D%7B2%7D%29)
Note that tangent function can be solved using the formula y/x
where x and y are the coordinates of the angle.
This will be :
![\frac{\sqrt[]{2}}{2}\div(-\frac{\sqrt[]{2}}{2})=-1](https://tex.z-dn.net/?f=%5Cfrac%7B%5Csqrt%5B%5D%7B2%7D%7D%7B2%7D%5Cdiv%28-%5Cfrac%7B%5Csqrt%5B%5D%7B2%7D%7D%7B2%7D%29%3D-1)
The answer is -1
The probability can be modeled using the following formula:
wherein X follows the density
Now for k = 3 we get:
The probability we are looking for is 0.15.
Do you have any question ?
It’s 20 degrees because all triangles are all equal up to 180° and so if you add 135° to 25° you get 160° and so minus 160 from 180 and you’ll get 20°
