<span>So we want to know why is a car racetrack built with a steep inward slope. When a car is moving on a circular path, it experiences a centrifugal force. This force is bigger as the car speed rises. So to counteract that force the steep inward slope is creating a force component towards the center of the circle that comes from the car's own weight so the car doesn't slide off the road. </span>
Question 24.
The Environmental Protection Agency is a regulatory agency that protects human and environmental life. Because it is a regulatory agency, it oversees all actions that has a direct effect on the environment. Letter A could be an answer, but not the best. The EPA does not trust environmentalists because they still have to inspect the ship. Maybe the ship would drive away fishes from their aquatic homes which would cause an imbalance in the ecosystem. So, the best answer would be letter C.
Question 25:
Gravity is a force of attraction that acts as the pull towards the object's center. According to Newton's Law of Universal Gravitation, the force of gravity is directly proportional to the mass, and inversely proportional to distance. The heavier and nearer the objects are, the greater the force of gravity. Every object in the world is acted upon by gravity, whether at rest or moving. Therefore, the answer is <span>B.
Question 26:
Power is the amount of work done per unit time. So, if time is not changed and work increases, the power will have to increase as well. The answer is C.
Question 27:
In electricity, the power of the load in a circuit is equal to the product of its voltage and current. Therefore, voltage and current are directly proportional to power. But they are inversely proportional to each other. So, if voltage increases, the power also increases. Therefore, the answer is B.
Question 28:
Hybrid cars work on the energy both coming from oil and electricity. Electricity is a more expensive fuel than oil. So, you will expect that hybrid cars are much more expensive. Electricity comes from batteries, which is made up of electrolyte solutions of metals. They are non-renewable source as well. The only advantage is that, batteries do not emit pollutant gases unlike oil. These gases deteriorate the ozone layer which protects the Earth from exposure to UV rays. Therefore, the answer is B.</span>
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
Answer:
The number of crates is 84580.
Explanation:
mass, m = 30 kg
height, h = 0.9 mm
Power, P = 0.5 hp = 0.5 x 746 W = 373 W
time, t = 1 minute = 60 s
Let the number of crates is n.
Power is given by the rate of doing work.
