Answer:
70 m.
Explanation:
Given,
Frequency, f = 20 HZ
speed of sound, v = 1400 m/s
wavelength of the waves = ?
we know,
v = f λ
Hence, the wavelength of the wave is equal to 70 m.
Answer:
The correct answer is a. Both are the same
Explanation:
For this calculation we must use the gravitational attraction equation
F = G m M / r²
Where M will use the mass of the Earth, m the mass of the girl and r is the distance of the girl to the center of the earth that we consider spherical
To better visualize things, let's repair the equation a little
F = m (G M / r²)
The amount in parentheses called acceleration of gravity, entered the force called peos
g = G M / r²
F = W
W = m g
When analyzing this equation we see that the variation in the weight of the girl depends on the distance, which is the radius of the earth plus the height where the girl is
r = Re + h
Re = 6.37 10⁶ m
r² = (Re + h)²
r² = Re² (1 + h / Re)²
Let's replace
W = m (GM / Re²) (1+ h / Re)⁻²
W = m g (1+ h / Re)⁻²
This is the exact expression for weight change with height, but let's look at its values for some reasonable heights h = 6300 m (very high mountain)
h / Re = 10
⁻³
(1+ h / Re)⁻² = 0.999⁻²
Therefore, the negligible weight reduction, therefore, for practical purposes the weight does not change with the height of the mountain on Earth
The correct answer is a
The centripetal acceleration of the car is 48,800 mi/h2
Answer:
Q = 50.25 [J]
Explanation:
To solve this problem we must use the following equation that relates the temperature change with the mass and with the specific heat.
Q = m*Cp*(DT)
where:
Q = energy in form of heat [J]
m = mass = 5 [g] = 0.005 [kg]
Cp = specific heat = 1005 [J/kg*°C]
DT = temperature change = 10 [°C]
Now replacing:
Q = 0.005*1005*10
Q = 50.25 [J]
