The answer is A. Have you ever heard the saying, opposites attract? That comes from magnetism. Like poles repel each other while opposites attract.
Answer:
$1.26
Explanation:
Power =energy/ time
energy =powerxtime
energy =50x31x24=37200
=37.2kwh
1kwh =3.39
37.2kwh=3.39x37.2=126.108cent
=$1.26
To solve this problem it is necessary to apply the kinematic equations of motion and Hook's law.
By Hook's law we know that force is defined as,
![F= kx](https://tex.z-dn.net/?f=F%3D%20kx)
Where,
k = spring constant
x = Displacement change
PART A) For the case of the spring constant we can use the above equation and clear k so that
![k= \frac{F}{x}](https://tex.z-dn.net/?f=k%3D%20%5Cfrac%7BF%7D%7Bx%7D)
![k = \frac{mg}{x}](https://tex.z-dn.net/?f=k%20%3D%20%5Cfrac%7Bmg%7D%7Bx%7D)
![k= \frac{77.2*9.8}{0.0637}](https://tex.z-dn.net/?f=k%3D%20%5Cfrac%7B77.2%2A9.8%7D%7B0.0637%7D)
![k = 11876.92N/m](https://tex.z-dn.net/?f=k%20%3D%2011876.92N%2Fm)
Therefore the spring constant for each one is 11876.92/2 = 5933.46N/m
PART B) In the case of speed we can obtain it through the period, which is given by
![T = \frac{2\pi}{\omega}](https://tex.z-dn.net/?f=T%20%3D%20%5Cfrac%7B2%5Cpi%7D%7B%5Comega%7D)
Re-arrange to find \omega,
![\omega = \frac{2\pi}{T}](https://tex.z-dn.net/?f=%5Comega%20%3D%20%5Cfrac%7B2%5Cpi%7D%7BT%7D)
![\omega = \frac{2\pi}{2.14}](https://tex.z-dn.net/?f=%5Comega%20%3D%20%5Cfrac%7B2%5Cpi%7D%7B2.14%7D)
![\omega = 2.93rad/s](https://tex.z-dn.net/?f=%5Comega%20%3D%202.93rad%2Fs)
Then through angular kinematic equations where angular velocity is given as a function of mass and spring constant we have to
![\omega^2 = \frac{k}{m}](https://tex.z-dn.net/?f=%5Comega%5E2%20%3D%20%5Cfrac%7Bk%7D%7Bm%7D)
![m = \frac{k}{\omega^2}](https://tex.z-dn.net/?f=m%20%3D%20%5Cfrac%7Bk%7D%7B%5Comega%5E2%7D)
![m = \frac{ 11876.92}{2.93}](https://tex.z-dn.net/?f=m%20%3D%20%5Cfrac%7B%2011876.92%7D%7B2.93%7D)
![m = 4093.55Kg](https://tex.z-dn.net/?f=m%20%3D%204093.55Kg)
Therefore the mass of the trailer is 4093.55Kg
PART C) The frequency by definition is inversely to the period therefore
![f = \frac{1}{T}](https://tex.z-dn.net/?f=f%20%3D%20%5Cfrac%7B1%7D%7BT%7D)
![f = \frac{1}{2.14}](https://tex.z-dn.net/?f=f%20%3D%20%5Cfrac%7B1%7D%7B2.14%7D)
![f = 0.4672 Hz](https://tex.z-dn.net/?f=f%20%3D%200.4672%20Hz)
Therefore the frequency of the oscillation is 0.4672 Hz
PART D) The time it takes to make the route 10 times would be 10 times the period, that is
![t_T = 10*T](https://tex.z-dn.net/?f=t_T%20%3D%2010%2AT)
![t_T = 10 *2.14s](https://tex.z-dn.net/?f=t_T%20%3D%2010%20%2A2.14s)
![t_T = 21.4s](https://tex.z-dn.net/?f=t_T%20%3D%2021.4s)
Therefore the total time it takes for the trailer to bounce up and down 10 times is 21.4s
They are incline hope this helps!
Rubber is a insulator so current cannot pass through it where as metal is a conductor which allows current to pass through it