Answer:
a) t=1s
y = 10.1m
v=5.2m/s
b) t=1.5s
y =11.475 m
v=0.3m/s
c) t=2s
y =10.4 m
v=-4.6m/s (The minus sign (-) indicates that the ball is already going down)
Explanation:
Conceptual analysis
We apply the free fall formula for position (y) and speed (v) at any time (t).
As gravity opposes movement the sign in the equations is negative.:
y = vi*t - ½ g*t2 Equation 1
v=vit-g*t Equation 2
y: The vertical distance the ball moves at time t
vi: Initial speed
g= acceleration due to gravity
v= Speed the ball moves at time t
Known information
We know the following data:
Vi=15 m / s
t=1s ,1.5s,2s
Development of problem
We replace t in the equations (1) and (2)
a) t=1s
=15-4.9=10.1m
v=15-9.8*1 =15-9.8 =5.2m/s
b) t=1.5s
=22.5-11.025=11.475 m
v=15-9.8*1.5 =15-14.7=0.3m/s
c) t=2s
= 30-19.6=10.4 m
v=15-9.8*2 =15-19.6=-4.6m/s (The minus sign (-) indicates that the ball is already going down)
[I researched for you, since I am not in that particular level to know that knowledge yet. I assure this is accurate info :)]
The answer is A, red.
"Remember, the color you see is light REFLECTING off the surface of that object. If all colors are absorbed in to the surface EXCEPT red, red must be reflected, and you'll see red." - Yahoo User @Chap
Answer:
391.5 J
Explanation:
The amount of work done can be calculated using the formula:
- W = F║d
- where the force is parallel to the displacement
Looking at the formula, we can see that the mass of the object does not affect the work done on it.
Substitute the force applied and the displacement of the object into the equation.
- W = (87 N)(4.5 m)
- W = 391.5 J
The amount of work done on the object is 391.5 J in order to move it 4.5 meters with an applied force of 87 Newtons.
Since the frequency of sound in a medium is constant, therefore, the concert-goers would hear the low notes and high notes at the same time.
<h3>What is a dispersive medium?</h3>
A dispersive medium is a medium which spreads out or disperses a substance passing through it.
Since CO2 is a dispersive medium, it means sound waves passing through it would be dispersed based on wavelength.
The note of a sound depends on its frequency, the higher the frequency, the higher the note.
Frequency of sound is constant, therefore, the concert-goers would hear the low notes and high notes at the same time.
Learn more about dispersion of sound at: brainly.com/question/781734