Answer:
7.3 g/cubic cm
Explanation:
You divide the mass by the volume to calculate the density of the metal.
146g ÷ 20cm³ = 7.3g/cm³
The question is: You have 500g of ethyl alcohol at a temperature of -40 ° C. How much heat is needed to transform it into steam at a temperature of 150ºC?
Answer: 233700 J heat is needed to transform ethyl alcohol into steam at a temperature of
to
.
Explanation:
Given: Mass = 500 g
Initial temperature = ![-40^{o}C](https://tex.z-dn.net/?f=-40%5E%7Bo%7DC)
Final temperature = ![150^{o}C](https://tex.z-dn.net/?f=150%5E%7Bo%7DC)
The standard value of specific heat of ethyl alcohol is
.
Formula used to calculate the heat energy is as follows.
![q = m \times C \times (T_{2} - T_{1})](https://tex.z-dn.net/?f=q%20%3D%20m%20%5Ctimes%20C%20%5Ctimes%20%28T_%7B2%7D%20-%20T_%7B1%7D%29)
where,
q = heat energy
m = mass of substance
C = specific heat
= initial temperature
= final temperature
Substitute the values into above formula as follows.
![q = m \times C \times (T_{2} - T_{1})\\= 500 g \times 2.46 J/g^{o}C \times [150 - (-40)]^{o}C\\= 233700 J](https://tex.z-dn.net/?f=q%20%3D%20m%20%5Ctimes%20C%20%5Ctimes%20%28T_%7B2%7D%20-%20T_%7B1%7D%29%5C%5C%3D%20500%20g%20%5Ctimes%202.46%20J%2Fg%5E%7Bo%7DC%20%5Ctimes%20%5B150%20-%20%28-40%29%5D%5E%7Bo%7DC%5C%5C%3D%20233700%20J)
Thus, we can conclude that 233700 J heat is needed to transform ethyl alcohol into steam at a temperature of
to
.
Answer:
![A = 0.2875 m^2](https://tex.z-dn.net/?f=A%20%3D%200.2875%20m%5E2)
Explanation:
As we know that
![Q = 4.6 \mu C](https://tex.z-dn.net/?f=Q%20%3D%204.6%20%5Cmu%20C)
E = 1.8 kV/mm
now we know that electric field between the plated of capacitor is given as
![E = \frac{\sigma}{\epsilon_0}](https://tex.z-dn.net/?f=E%20%3D%20%5Cfrac%7B%5Csigma%7D%7B%5Cepsilon_0%7D)
now we will have
![1.8 \times 10^6 = \frac{\sigma}{\epsilon_0}](https://tex.z-dn.net/?f=1.8%20%5Ctimes%2010%5E6%20%3D%20%5Cfrac%7B%5Csigma%7D%7B%5Cepsilon_0%7D)
![\sigma = (1.8 \times 10^6)(8.85 \times 10^{-12})](https://tex.z-dn.net/?f=%5Csigma%20%3D%20%281.8%20%5Ctimes%2010%5E6%29%288.85%20%5Ctimes%2010%5E%7B-12%7D%29)
![\sigma = 1.6 \times 10^{-5} C/m^2](https://tex.z-dn.net/?f=%5Csigma%20%3D%201.6%20%5Ctimes%2010%5E%7B-5%7D%20C%2Fm%5E2)
now we have
![\sigma = \frac{Q}{A}](https://tex.z-dn.net/?f=%5Csigma%20%3D%20%5Cfrac%7BQ%7D%7BA%7D)
now we have area of the plates of capacitor
![A = \frac{Q}{\sigma}](https://tex.z-dn.net/?f=A%20%3D%20%5Cfrac%7BQ%7D%7B%5Csigma%7D)
![A = \frac{4.6 \times 10^{-6}}{1.6 \times 10^{-5}}](https://tex.z-dn.net/?f=A%20%3D%20%5Cfrac%7B4.6%20%5Ctimes%2010%5E%7B-6%7D%7D%7B1.6%20%5Ctimes%2010%5E%7B-5%7D%7D)
![A = 0.2875 m^2](https://tex.z-dn.net/?f=A%20%3D%200.2875%20m%5E2)
Answer:
A) Air resistance acts in a direction opposite the the fall of an object reducing it by doing work against the weight of the object due to gravity.
B) using a ping pong ball, the time of fall will be greatly reduced since it has little weight (its mass x acceleration due to gravity) against the air resistance. The net downward force of the weight and the air resistance will be small.
C) No, I wouldn't expect them to fall at the same time. The steel ball will have more weight compared to the ping pong ball and hence it will have a larger net force downwards.
D) If they are both released from a 6 m height, the steel ball will fall to the ground first since it has a larger net force downwards.
Answer:
T = 4.42 10⁴ N
Explanation:
this is a problem of standing waves, let's start with the open tube, to calculate the wavelength
λ = 4L / n n = 1, 3, 5, ... (2n-1)
How the third resonance is excited
m = 3
L = 192 cm = 1.92 m
λ = 4 1.92 / 3
λ = 2.56 m
As in the resonant processes, the frequency is maintained until you look for the frequency in this tube, with the speed ratio
v = λ f
f = v / λ
f = 343 / 2.56
f = 133.98 Hz
Now he works with the rope, which oscillates in its second mode m = 2 and has a length of L = 37 cm = 0.37 m
The expression for standing waves on a string is
λ = 2L / n
λ = 2 0.37 / 2
λ = 0.37 m
The speed of the wave is
v = λ f
As we have some resonance processes between the string and the tube the frequency is the same
v = 0.37 133.98
v = 49.57 m / s
Let's use the relationship of the speed of the wave with the properties of the string
v = √ T /μ
T = v² μ
T = 49.57² 18
T = 4.42 10⁴ N