The answer is
2.5 N
B
this needs to be 20 letters long so this part doesn't matter
Given:
f1 = 20 Hz
f2 = 20000 Hz
speed of sound at 20 degrees celcius = 343 m/s
Solution:
for f1 = 20 Hz,
Using the equation:
lambda = speed of sound / f1 = 343 / 20 = 17.15 m
For f2:
lambda = speed of sound / f2 = 343 / 20000 = 0.01775 m
Therefore the wavelength range of audible sound in air would be 17.15 m to 0.01775 m.
Answer:
ΔT = 40.91 °C
Explanation:
First we find the kinetic energy of one hit to the nail:
K.E = (1/2)mv²
where,
K.E = Kinetic energy = ?
m = mass of hammer = 1.6 kg
v = speed of hammer = 7.7 m/s
Therefore,
K.E = (1/2)(1.6 kg)(7.7 m/s)²
K.E = 47.432 J
Now, for 10 hits:
K.E = (10)(47.432 J)
K.E = 474.32 J
Now, we calculate the heat energy transferred (Q) to the nail. As, it is the 59% of K.E. Therefore,
Q = (0.59)K.E
Q = (0.59)(474.32 J)
Q = 279.84 J
The change in energy of nail is given as:
Q = mCΔT
where,
m = mass of nail = 7.6 g = 0.0076 kg
C = specific heat capacity of aluminum = 900 J/kg.°C
ΔT = Increase in temperature = ?
Therefore,
279.84 J = (0.0076 kg)(900 J/kg.°C)ΔT
ΔT = (279.84 J)/(6.84 J/°C)
<u>ΔT = 40.91 °C</u>
From the choices provided, the better answer is ' T ' .
Answer:
The correct answer is - 200000 J
Explanation:
We use the formula of kinetic energy:
The formula to calculate kinetic energy is,
Here,
Ec =1/2 x m x v^2
The mass of the roller coaster is, m = 1000 k
g
The speed of the roller coaster is, v = 20.0 m/s
Therefore,
Ec=1/2 x 1000kg x (20m/s)^2 = 200.000Joule
200,000J
