-6 uh 89 0 -+= 62 uwuwhhiwhiuhwiuhwuihhishishoknsk
Answer: 17.68 s
Explanation:
This problem is a good example of Vertical motion, where the main equation for this situation is:
(1)
Where:
is the height of the ball when it hits the ground
is the initial height of the ball
is the initial velocity of the ball
is the time when the ball strikes the ground
is the acceleration due to gravity
Having this clear, let's find
from (1):
(2)
Rewritting (2):
(3)
This is a quadratic equation (also called equation of the second degree) of the form
, which can be solved with the following formula:
(4)
Where:



Substituting the known values:
(5)
Solving (5) we find the positive result is:

Answer:
7 m/s
Explanation:
To solve this problem you must use the conservation of energy.

That math speak for, initial kinetic energy plus initial potential energy equals final kinetic energy plus final potential energy.
The initial PE (potential energy) is 0 because it hasn't been raised in the air yet. The final KE (kinetic energy) is 0 because it isn't moving. This gives the following:


K1=U2

Solve for v

Input known values and you get 7 m/s.
A red apple absorbs all colors of visible light except red, so red light
is the only light left to bounce off of the apple toward our eyes.
(This is a big part of the reason that we call it a "red" apple.)
Here's how the various items on the list make out when they hit the apple:
<span>Red . . . . . reflected
Orange . . absorbed
Yellow . . . </span><span><span>absorbed
</span>Green . </span><span><span>. . absorbed
</span>Blue . . </span><span><span>. . absorbed
</span>Violet .</span><span> . . absorbed</span>
<span>Black . . . no light; not a color
White . . . has all colors in it</span>
Answer:
.409 N
Explanation:
For this to balance, the moments around the fulcrum must sum to zero.
On the left you have .21 ( is that down? I will assume it is)
Counterclockwise moments :
.21 * 40 + 1.0 * 20
Clockwise moments :
.5 * 20 + F * 45
these moments must equal each other
.21*40 + 1 *20 = .5 * 20 + F * 45
F = .409 N