Answer:
The sound travelled 516 meters before bouncing off a cliff.
Explanation:
The sound is an example of mechanical wave, which means that it needs a medium to propagate itself at constant speed. The time needed to hear the echo is equal to twice the height of the canyon divided by the velocity of sound. In addition, the speed of sound through the air at a temperature of 20 ºC is approximately 344 meters per second. Then, the height of the canyon can be derived from the following kinematic formula:
(1)
Where:
- Height, measured in meters.
- Velocity of sound, measured in meters per second.
- Time, measured in seconds.
If we know that 
and 
, then the height of the canyon is:
The sound travelled 516 meters before bouncing off a cliff.
If time is the x axis and distance is the y axis then yes, in the case that time is going by but distance remains the same.
Answer:
a) t = 0.90 s, b) t = 0.815 s, c) t = 0.90 s, d) x = 3.6 m, e) t = 0.639 s
Explanation:
all these exercises are about kinematics
a) The body is released from rest,
y = y₀ + v₀ t - ½ g t²
in this case when reaching the ground y = 0 and its initial velocity is vo = 0
0 = y₀ + 0 - ½ g t²
t² = 2 y₀ / g
t² = 2 4 /9.81
t² = 0.815
t = √0.815
t = 0.90 s
b) It is thrown upwards at v₀ = 4 m / s
y = y₀ + v₀ t - ½ g t²
in this case the initial and final height is the same
y = y₀ = 0
0 = v₀ t -1/2 g t²
t = 2 v₀ / g
t = 2 4 /9.81
t = 0.815 s
c) the ball is at y₀ = 4 m and its initial velocity is horizontal v₀ = 4 m / s
y = y₀ + v_{oy} t - ½ g t²
0 = y₀ + 0 - ½ g t²
t² = 2 i / g
t² = 2 4 / 9.81
t² = 0.815
t = 0.90 s
d) the horizontal distance traveled is
x = v₀ₓ t
x = 4 0.90
x = 3.6 m
e) We can calculate the time to fall from I = 2 m
y = y₀ + v_{oy} t - ½ g t²
0 = y₀ + 0 - ½ g t²
t² = 2 y₀i / g
t² = 2 2 /9.81
t² = 0.4077
t = 0.639 s
Therefore, when making measurements, you should find readings around this value.
For A: LED outdoor lighting.
Because you want it to be able to withstand outdoor conditions. If it can’t withstand... there’s no light... no light... no advertisement.
For B: it would be lithonium lights. It’s found in most offices and gives the best light for working day or night.
For C: you’ll want elevated lights so they are noticed for the plane to land and for people and others to see.
For D: you want white light and you want it to also be able to withstand outdoor conditions. Cars and people need to see at night, especially at night. Solar would be a great choice.
Hope this helps! I tried hard.
