Answer:
b) 0.5 N
Explanation:
From coulomb's law,
F = kq'q/r².................... Equation 1
Where F =force of repulsion between the charges, q' = first charge, q = second charge, r = distance between the charges, k = proportionality constant.
q'q = Fr²/k........................... Equation 2
Given: F = 2 N, r = 1 m, k = 9.0×10⁹ Nm²/C²
Substituting into equation 2
q'q = 2(1)²/(9.0×10⁹)
q'q = 2/9.0×10⁹ C².
If the distance between the charges is increased to 2 meters,
r = 2 m, q'q = 2/9.0×10⁹ C².
Substitute into equation 1
F = 9.0×10⁹(2/9.0×10⁹)/2²
F = 2/4
F = 1/2 = 0.5 N.
The right option is b) 0.5 N
Answer:
a. 5 batteries b. 1050 mAh
Explanation:
Here is the complete question
A student project is required to be portable and hand held. It requires 6 V DC power at a current of 150 mA. The batteries for the power supply must last for a minimum of 7 hours of continuous operation. NiMH rechargeable batteries in AA size are to be used. A) How many batteries are needed? B) What mAh capacity should the batteries have?
Solution
A) How many batteries are needed?
Since the nominal voltage for a single NiMH battery is 1.2 V per battery and we require 6V DC power, we combine the batteries in series to obtain a total voltage of 6 V. The number of batteries required, n = total voltage/voltage per cell = 6V/1.2V per battery = 5 batteries
So, the number of batteries needed is 5.
B) What mAh capacity should the batteries have?
Since the batteries are in series, they would each deliver a current of 150 mA. Since we require a current of 150 mA for 7 hours, the number of milliampere-hours capacity mAh of batteries required is Q = It where I = current = 150 mA and t = time = 7 hours.
So, Q = It = 150 mA × 7 h = 1050 mAh.
So, the batteries should have a mAh of 1050 mAh
Answer:
(177.94 ± 3.81) cm^2
Explanation:
l + Δl = 21.7 ± 0.2 cm
b + Δb = 8.2 ± 0.1 cm
Area, A = l x b = 21.7 x 8.2 = 177.94 cm^2
Now use error propagation
So, the area with the error limits is written as
A + ΔA = (177.94 ± 3.81) cm^2
Answer: <u>In a divergent plate boundary</u>, seafloor spreading taking place. It leads to the formation of oceans as new materials are added here along the mid-oceanic ridge. There occur volcanism and shallow-focus earthquakes.
<u>In a convergent plate boundary</u>, two plates collide to form high mountain belts and also volcanic eruptions take place. There occur long chains of volcanic as well as island arcs, in association with deep-focus earthquakes.
<u>In a transform plate boundary</u>, two plates slide past each other, conserving the plates. Shallow-focus earthquakes are generated here.
The earth has experienced various geological processes, such as weathering and erosion of rocks, earthquakes, volcanic eruptions, mass extinction events, plate tectonic movements and many more. These continuous processes have configured the present shape of the earth's surface.
For example, the breaking up of the supercontinent Pangea divided into Laurasia and Gondwanaland and subsequently formed the present scenario. This separation of continents has taken place due to the convection current that generates in the mantle.
