Answer:
Fnet = 12 N
Explanation:
Force on a point charge due to another point charge = kq1q2 / d^2
Force on +32uC = due to + 20uC + due to -60uC
where uC = 1 x 10^-6 C and k = 9 x 10^9 N m^2 / C^2
Net Force =
![= \frac{1}{4\pi \epsilon _0} [\frac{32 \times 10^-^6 \times60\times10^-^6}{(60/100)^2}-\frac{32 \times 10^-^6 \times20\times10^-^6}{ (40/100)^2} ]](https://tex.z-dn.net/?f=%3D%20%5Cfrac%7B1%7D%7B4%5Cpi%20%5Cepsilon%20_0%7D%20%5B%5Cfrac%7B32%20%5Ctimes%2010%5E-%5E6%20%5Ctimes60%5Ctimes10%5E-%5E6%7D%7B%2860%2F100%29%5E2%7D-%5Cfrac%7B32%20%5Ctimes%2010%5E-%5E6%20%5Ctimes20%5Ctimes10%5E-%5E6%7D%7B%20%2840%2F100%29%5E2%7D%20%20%5D)
![F_{net}=9 \times10^9\times 10^-^1^2[\frac{32\times60\times10^4}{60\times60} -\frac{32\times20\times10^4}{40\times40} ]](https://tex.z-dn.net/?f=F_%7Bnet%7D%3D9%20%5Ctimes10%5E9%5Ctimes%2010%5E-%5E1%5E2%5B%5Cfrac%7B32%5Ctimes60%5Ctimes10%5E4%7D%7B60%5Ctimes60%7D%20-%5Cfrac%7B32%5Ctimes20%5Ctimes10%5E4%7D%7B40%5Ctimes40%7D%20%5D)
![=90[32(\frac{80-60}{60\times 80} )]\\\\=90\times32\times0.004167\\\\=12N](https://tex.z-dn.net/?f=%3D90%5B32%28%5Cfrac%7B80-60%7D%7B60%5Ctimes%2080%7D%20%29%5D%5C%5C%5C%5C%3D90%5Ctimes32%5Ctimes0.004167%5C%5C%5C%5C%3D12N)
Fnet = 12 N
The minimum force required to lift the box at constant velocity is determined as 274.4 N.
<h3>
Minimum force required</h3>
The minimum force required to lift the box at constant velocity is the tension in one of the pulleys, and the magnitude is calculated as follows;
2T = mg
where;
- m is mass of the box
- T is the minimum force required
2T = mg
T = mg/2
T = (56 x 9.8)/2
T = 274.4 N
Learn more about minimum force here: https://brainly.in/question/47873510
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Answer:
Explanation:
decrease in energy of the transferred charge
= Voltage x charge
= 2.86 x 10⁹ x 23.1
= 66.067 x 10⁹ J
the final speed of the automobile be V
1/2 m v² = 66.067 x 10⁹
v² = 66.067 x 10⁹ x 2 / 1519
= .08698 x10⁹
= 87 x 10⁶
v = 9.32 x 10³ m / s
We use the radioactive decay equation for this problem which is expressed as:
An = Aoe^-kt
An is the remaining amount after time t, Ao is the initial amount and k is a constant.
First, we determine the k from the half life as follows:
An/Ao = 1/2 = e^-k(14.4)
k = 0.04814
Then, we can calculate An after 28.8 yr.
An = 1000 e^-0.04814(28.8)
An = 250 g