Answer: 7.41 m/s
Explanation: By using the law of of energy, kinetic energy of the brick as it falls equals the potential energy before falling. 
Kinetic energy = mv²/2, potential energy = mgh 
mv²/2 = mgh 
v²/2 = gh 
v² = 2gh 
v = √2gh 
Where g = 9.8 m/s², h = 2.80m
v = √2×9.8×2.8 = 7.41 m/s
 
        
             
        
        
        
Answer:
Explanation:
60 meters is he answer for this question
 
        
             
        
        
        
Although the video is not found here, the sentence makes reference to the transmission spectrum of colored filters.
<h3>What is the transmission spectrum?</h3>
The transmission spectrum indicates the light portion having a given wavelength that can be passed through a filter.
This spectrum (transmission spectrum) depends on the physical separation of the particles that form the filter.
In conclusion, although the video is not found here, the sentence makes reference to the transmission spectrum of colored filters.
Learn more about the transmission spectrum here:
brainly.com/question/1287536
#SPJ1
 
        
             
        
        
        
Answer:
a) t = 20 [s]
b) Can't land
Explanation:
To solve this problem we must use kinematics equations, it is of great importance to note that when the plane lands it slows down until it reaches rest, ie the final speed will be zero.
a)

where:
Vf = final velocity = 0
Vi = initial velocity = 100 [m/s]
a = desacceleration = 5 [m/s^2]
t = time [s]
Note: the negative sign of the equation means that the aircraft slows down as it stops.
0 = 100 - 5*t
5*t = 100
t = 20 [s]
b)
Now we can find the distance using the following kinematics equation.

x - xo = distance [m]
x -xo = (0*20) + (0.5*5*20^2)
x - xo =  1000 [m]
1000 [m] = 1 [km] 
And the runaway is 0.8 [km], therefore the jetplane needs 1 [km] to land. So the jetpalne can't land