I'd say move faster, unless it's asking something else.
Answer:
1. Largest force: C; smallest force: B; 2. ratio = 9:1
Explanation:
The formula for the force exerted between two charges is
![F=K\dfrac{ q_{1}q_{2}}{r^{2}}](https://tex.z-dn.net/?f=F%3DK%5Cdfrac%7B%20q_%7B1%7Dq_%7B2%7D%7D%7Br%5E%7B2%7D%7D)
where K is the Coulomb constant.
q₁ and q₂ are also identical and constant, so Kq₁q₂ is also constant.
For simplicity, let's combine Kq₁q₂ into a single constant, k.
Then, we can write
![F=\dfrac{k}{r^{2}}](https://tex.z-dn.net/?f=F%3D%5Cdfrac%7Bk%7D%7Br%5E%7B2%7D%7D)
1. Net force on each particle
Let's
- Call the distance between adjacent charges d.
- Remember that like charges repel and unlike charges attract.
Define forces exerted to the right as positive and those to the left as negative.
(a) Force on A
![\begin{array}{rcl}F_{A} & = & F_{B} + F_{C} + F_{D}\\& = & -\dfrac{k}{d^{2}} - \dfrac{k}{(2d)^{2}} +\dfrac{k}{(3d)^{2}}\\& = & \dfrac{k}{d^{2}}\left(-1 - \dfrac{1}{4} + \dfrac{1}{9} \right)\\\\& = & \dfrac{k}{d^{2}}\left(\dfrac{-36 - 9 + 4}{36} \right)\\\\& = & \mathbf{-\dfrac{41}{36} \dfrac{k}{d^{2}}}\\\\\end{array}](https://tex.z-dn.net/?f=%5Cbegin%7Barray%7D%7Brcl%7DF_%7BA%7D%20%26%20%3D%20%26%20F_%7BB%7D%20%2B%20F_%7BC%7D%20%2B%20F_%7BD%7D%5C%5C%26%20%3D%20%26%20-%5Cdfrac%7Bk%7D%7Bd%5E%7B2%7D%7D%20%20-%20%5Cdfrac%7Bk%7D%7B%282d%29%5E%7B2%7D%7D%20%20%2B%5Cdfrac%7Bk%7D%7B%283d%29%5E%7B2%7D%7D%5C%5C%26%20%3D%20%26%20%5Cdfrac%7Bk%7D%7Bd%5E%7B2%7D%7D%5Cleft%28-1%20-%20%5Cdfrac%7B1%7D%7B4%7D%20%2B%20%5Cdfrac%7B1%7D%7B9%7D%20%5Cright%29%5C%5C%5C%5C%26%20%3D%20%26%20%5Cdfrac%7Bk%7D%7Bd%5E%7B2%7D%7D%5Cleft%28%5Cdfrac%7B-36%20-%209%20%2B%204%7D%7B36%7D%20%5Cright%29%5C%5C%5C%5C%26%20%3D%20%26%20%5Cmathbf%7B-%5Cdfrac%7B41%7D%7B36%7D%20%5Cdfrac%7Bk%7D%7Bd%5E%7B2%7D%7D%7D%5C%5C%5C%5C%5Cend%7Barray%7D)
(b) Force on B
![\begin{array}{rcl}F_{B} & = & F_{A} + F_{C} + F_{D}\\& = & \dfrac{k}{d^{2}} - \dfrac{k}{d^{2}} + \dfrac{k}{(2d)^{2}}\\& = & \dfrac{k}{d^{2}}\left(\dfrac{1}{4} \right)\\\\& = &\mathbf{\dfrac{1}{4} \dfrac{k}{d^{2}}}\\\\\end{array}](https://tex.z-dn.net/?f=%5Cbegin%7Barray%7D%7Brcl%7DF_%7BB%7D%20%26%20%3D%20%26%20F_%7BA%7D%20%2B%20F_%7BC%7D%20%2B%20F_%7BD%7D%5C%5C%26%20%3D%20%26%20%5Cdfrac%7Bk%7D%7Bd%5E%7B2%7D%7D%20%20-%20%5Cdfrac%7Bk%7D%7Bd%5E%7B2%7D%7D%20%20%2B%20%5Cdfrac%7Bk%7D%7B%282d%29%5E%7B2%7D%7D%5C%5C%26%20%3D%20%26%20%5Cdfrac%7Bk%7D%7Bd%5E%7B2%7D%7D%5Cleft%28%5Cdfrac%7B1%7D%7B4%7D%20%5Cright%29%5C%5C%5C%5C%26%20%3D%20%26%5Cmathbf%7B%5Cdfrac%7B1%7D%7B4%7D%20%5Cdfrac%7Bk%7D%7Bd%5E%7B2%7D%7D%7D%5C%5C%5C%5C%5Cend%7Barray%7D)
(C) Force on C
![\begin{array}{rcl}F_{C} & = & F_{A} + F_{B} + F_{D}\\& = & \dfrac{k}{(2d)^{2}} + \dfrac{k}{d^{2}} + \dfrac{k}{d^{2}}\\& = & \dfrac{k}{d^{2}}\left( \dfrac{1}{4} +1 + 1 \right)\\\\& = & \dfrac{k}{d^{2}}\left(\dfrac{1 + 4 + 4}{4} \right)\\\\& = & \mathbf{\dfrac{9}{4} \dfrac{k}{d^{2}}}\\\\\end{array}](https://tex.z-dn.net/?f=%5Cbegin%7Barray%7D%7Brcl%7DF_%7BC%7D%20%26%20%3D%20%26%20F_%7BA%7D%20%2B%20F_%7BB%7D%20%2B%20F_%7BD%7D%5C%5C%26%20%3D%20%26%20%5Cdfrac%7Bk%7D%7B%282d%29%5E%7B2%7D%7D%20%2B%20%5Cdfrac%7Bk%7D%7Bd%5E%7B2%7D%7D%20%20%2B%20%5Cdfrac%7Bk%7D%7Bd%5E%7B2%7D%7D%5C%5C%26%20%3D%20%26%20%5Cdfrac%7Bk%7D%7Bd%5E%7B2%7D%7D%5Cleft%28%20%5Cdfrac%7B1%7D%7B4%7D%20%2B1%20%2B%201%20%5Cright%29%5C%5C%5C%5C%26%20%3D%20%26%20%5Cdfrac%7Bk%7D%7Bd%5E%7B2%7D%7D%5Cleft%28%5Cdfrac%7B1%20%2B%204%20%2B%204%7D%7B4%7D%20%5Cright%29%5C%5C%5C%5C%26%20%3D%20%26%20%5Cmathbf%7B%5Cdfrac%7B9%7D%7B4%7D%20%5Cdfrac%7Bk%7D%7Bd%5E%7B2%7D%7D%7D%5C%5C%5C%5C%5Cend%7Barray%7D)
(d) Force on D
![\begin{array}{rcl}F_{D} & = & F_{A} + F_{B} + F_{C}\\& = & -\dfrac{k}{(3d)^{2}} - \dfrac{k}{(2d)^{2}} - \dfrac{k}{d^{2}}\\& = & \dfrac{k}{d^{2}}\left( -\dfrac{1}{9} - \dfrac{1}{4} -1 \right)\\\\& = & \dfrac{k}{d^{2}}\left(\dfrac{-4 - 9 -36}{36} \right)\\\\& = & \mathbf{-\dfrac{49}{36} \dfrac{k}{d^{2}}}\\\\\end{array}](https://tex.z-dn.net/?f=%5Cbegin%7Barray%7D%7Brcl%7DF_%7BD%7D%20%26%20%3D%20%26%20F_%7BA%7D%20%2B%20F_%7BB%7D%20%2B%20F_%7BC%7D%5C%5C%26%20%3D%20%26%20-%5Cdfrac%7Bk%7D%7B%283d%29%5E%7B2%7D%7D%20%20-%20%5Cdfrac%7Bk%7D%7B%282d%29%5E%7B2%7D%7D%20%20-%20%5Cdfrac%7Bk%7D%7Bd%5E%7B2%7D%7D%5C%5C%26%20%3D%20%26%20%5Cdfrac%7Bk%7D%7Bd%5E%7B2%7D%7D%5Cleft%28%20-%5Cdfrac%7B1%7D%7B9%7D%20-%20%5Cdfrac%7B1%7D%7B4%7D%20-1%20%5Cright%29%5C%5C%5C%5C%26%20%3D%20%26%20%5Cdfrac%7Bk%7D%7Bd%5E%7B2%7D%7D%5Cleft%28%5Cdfrac%7B-4%20-%209%20-36%7D%7B36%7D%20%5Cright%29%5C%5C%5C%5C%26%20%3D%20%26%20%5Cmathbf%7B-%5Cdfrac%7B49%7D%7B36%7D%20%5Cdfrac%7Bk%7D%7Bd%5E%7B2%7D%7D%7D%5C%5C%5C%5C%5Cend%7Barray%7D)
(e) Relative net forces
In comparing net forces, we are interested in their magnitude, not their direction (sign), so we use their absolute values.
![F_{A} : F_{B} : F_{C} : F_{D} = \dfrac{41}{36} : \dfrac{1}{4} : \dfrac{9}{4} : \dfrac{49}{36}\ = 41 : 9 : 81 : 49\\\\\text{C experiences the largest net force.}\\\text{B experiences the smallest net force.}\\](https://tex.z-dn.net/?f=F_%7BA%7D%20%3A%20F_%7BB%7D%20%3A%20F_%7BC%7D%20%3A%20F_%7BD%7D%20%20%3D%20%20%5Cdfrac%7B41%7D%7B36%7D%20%3A%20%5Cdfrac%7B1%7D%7B4%7D%20%3A%20%5Cdfrac%7B9%7D%7B4%7D%20%3A%20%5Cdfrac%7B49%7D%7B36%7D%5C%20%3D%2041%20%3A%209%20%3A%2081%20%3A%2049%5C%5C%5C%5C%5Ctext%7BC%20experiences%20the%20largest%20net%20force.%7D%5C%5C%5Ctext%7BB%20experiences%20the%20smallest%20net%20force.%7D%5C%5C)
2. Ratio of largest force to smallest
![\dfrac{ F_{C}}{ F_{B}} = \dfrac{81}{9} = \mathbf{9:1}\\\\\text{The ratio of the largest force to the smallest is $\large \boxed{\mathbf{9:1}}$}](https://tex.z-dn.net/?f=%5Cdfrac%7B%20F_%7BC%7D%7D%7B%20F_%7BB%7D%7D%20%3D%20%5Cdfrac%7B81%7D%7B9%7D%20%3D%20%5Cmathbf%7B9%3A1%7D%5C%5C%5C%5C%5Ctext%7BThe%20ratio%20of%20the%20largest%20force%20to%20the%20smallest%20is%20%24%5Clarge%20%5Cboxed%7B%5Cmathbf%7B9%3A1%7D%7D%24%7D)
Since force = mass X acceleration, then the force he excerts on the earth (aka his weight) equals his mass times the force of gravity.
Therefore
W = (66 kg) X (9.8 m/ss)
W = 646.8 kgm/ss
kg m/ss are also known as Newtons, so your answer is...
646.8 N
Answer:
m = 56.5 kg
Explanation:
Since the addition of mass on one piston caused a change in pressure head at the other. Diameter of the piston calculated is used as 0.46 m
Δm*g / Area = p * g * Δh ..... Eq1
![m = \frac{p*h*A}{g}](https://tex.z-dn.net/?f=m%20%3D%20%5Cfrac%7Bp%2Ah%2AA%7D%7Bg%7D)
![m = \frac{850 * 0.4 * pi*0.46^2}{4*9.81}\\\\m= 56.5 kg](https://tex.z-dn.net/?f=m%20%3D%20%5Cfrac%7B850%20%2A%200.4%20%2A%20pi%2A0.46%5E2%7D%7B4%2A9.81%7D%5C%5C%5C%5Cm%3D%2056.5%20kg)
Answer:
The mmf required is
×
A
Explanation:
The Magnetomotive force (mmf) is given by the formula below
![F_{M} = Hl\\](https://tex.z-dn.net/?f=F_%7BM%7D%20%3D%20Hl%5C%5C)
where
is the Magnetomotive force (mmf)
is the Magnetic field strength
is the magnetic length
The magnetic permeability μ is given by
μ = ![B / H](https://tex.z-dn.net/?f=B%20%2F%20H)
Where
is the Magnetic flux density
and
is the Magnetic field strength
From the question,
= 1.2Wb/m^2
μ = 1600m
From μ = ![B / H](https://tex.z-dn.net/?f=B%20%2F%20H)
∴
μ
![H = 1.2 / 1600\\](https://tex.z-dn.net/?f=H%20%3D%201.2%20%2F%201600%5C%5C)
×
A/m
Now, for the Magnetomotive force (mmf)
![F_{M} = Hl\\](https://tex.z-dn.net/?f=F_%7BM%7D%20%3D%20Hl%5C%5C)
From the question
= 1.5 m
∴
×
× ![1.5](https://tex.z-dn.net/?f=1.5)
×![10^{-3} A](https://tex.z-dn.net/?f=10%5E%7B-3%7D%20A)
Hence, The mmf required is
×
A