In my text book for social studies it says a canal
Answer:
78.4 m
Explanation:
To obtain the height of the cliff;
We can use the Relation to obtain the final velocity, v
v = u + at
a = acceleration due to gravity = 9.8m/s²
v = 0 + (9.8*4)
v = 0 + 39.2
v = 39.2 m/s
To obtain the Height, S
v² = u² + 2aS
39.2^2 = 0 + 2(9.8)S
39.2^2 = 0 + 19.6S
1536.64 = 19.6S
S = 1536.64 / 19.6
S = 78.4 m
Answer:
The sound intensity is still the same. The sound intensity level does not depend on the number of sound sources but only the wave properties of the wave medium and the properties of the sound source. The wave properties of the medium includes the density and also the temperature.
Explanation:
Answer: The length of the shadow on the wall is decreasing by 0.6m/s
Explanation:
the specified moment in the problem, the man is standing at point D with his head at point E.
At that moment, his shadow on the wall is y=BC.
The two right triangles ΔABC and ΔADE are similar triangles. As such, their corresponding sides have equal ratios:
ADAB=DEBC
8/12=2/y,∴y=3 meters
If we consider the distance of the man from the building as x then the distance from the spotlight to the man is 12−x.
(12−x) /12=2/y
1− (1 /12x )=2 × 1/y
Let's take derivatives of both sides:
−1 / 12dx = −2 × 1 / y^2 dy
Let's divide both sides by dt:
−1/12⋅dx/dt=−2/y^2⋅dy/dt
At the specified moment:
dxdt=1.6 m/s
y=3
Let's plug them in:
−1/121.6) = - 2/9 × dy/dt
dy/dt = 1.6/12 ÷ 2/9
dy/dt = 1.6/12 × 9/2
dy/dt = 14.4/24 = 0.6m/s
The light from the sun is reflected by the moon, we see the part of the moon that the sun shines on.The change in the phases are created from the rotation of the moon around earth.We see a full moon when the sun is opposite of the moon. The side the sun shines on the moon is what we see.