Answer:
a) -4 N
b) +4 N
Explanation:
Draw a free body diagram for each block.
For the large block, there are 2 forces: 12 N pushing to the right, and F pushing to the left.
For the small block, there is 1 force, F pushing to the right.
There are also weight and normal forces in the vertical direction, but we can ignore those.
Sum of forces on the large block in the x direction:
∑F = ma
12 − F = 4a
Sum of forces on the small block in the x direction:
∑F = ma
F = 2a
2F = 4a
Substitute:
12 − F = 2F
12 = 3F
F = 4
The small block pushes on the large block 4 N to the left (-4 N).
The large block pushes on the small block 4 N to the right (+4 N).
<h3><u>
Full Question:</u></h3>
Which explanations provide support for continental drift theory? Check all that apply.
Dinosaurs lived on many continents.
Coal fields match up across continents.
Tropical plant fossils were found in Arctic areas.
Similar rock types are found across continents.
Evidence of glaciers can be found in South Africa.
Coal fields match up across continents.
Similar rock types are found across continents.
Tropical plant fossils were found in Arctic areas.
Evidence of glaciers can be found in South Africa.
<h3><u>
Explanation:</u></h3>
The way the continents on the earth shifts its position is explained by the Continental drift theory. Alfred Wegener was the one who fist proposed this theory in 1912. This theory also explains how similar rocks are formed on the different continents and also the reason why some of the animal and plant fossils looks similar.
The evidences that supports the continental drift theory can be Coal fields match up across continents. Fossils of Glossopteris supports the theory of continental drift with coal fields and coastlines
. The land features, climate changes are some of the evidences that also supports the theory of continental drift.The evidences of the glaciers that can be found in South Africa also supports the explanation of the continental drift.
Electric potential energy is defined as Ep=Q*V where Q is the magnitude of the charge and V is the potential difference. So when a charge moves between the points that have a potential difference, it's energy changes.
In our case:
Q=2e=2*(-1.6*10^-19) C
V=75 V
Ep=(-3.2*10^-19)*75
Ep=-2.4*10^-17 J
The change in potential energy of the charge is -2.4*10^-17 J
Answer:
-30 N/C
Explanation:
Since the potential changes from 0.90 V to 1.2 V when I move the probe 1 cm closer to the non-grounded electrode, the electric field is the gradient between the two points is given by E = -ΔV/Δx where ΔV = change in electric potential and Δx = distance of potential change = 1 cm = 0.01 m
Now ΔV = final potential - initial potential = 1.2 V - 0.90 V = 0.30 V
Since E = -ΔV/Δx
substituting the values of the variables into the equation, we have
E = -ΔV/Δx
E = -0.30 V/0.01 m
E = -30 V/m
Since 1 V/m = 1 N/C.
E = -30 N/C
So, the average electric field is -30 N/C
The magnitude and direction of the electric field in the wire are mathematically given as
![L &=[(v / L) v / m] \hat{i}](https://tex.z-dn.net/?f=L%20%26%3D%5B%28v%20%2F%20L%29%20v%20%2F%20m%5D%20%5Chat%7Bi%7D)
<h3>What is the magnitude and direction of the electric field in the wire?</h3>
Generally, the equation for is mathematically given as
A cylindrical wire that is straight and parallel to the x-axis has the following dimensions: length L, diameter d, resistivity p, diameter d, potential v, and z length. combining elements from both sides
E d 
![\begin{aligned}&-E \int_0^L d x=\int_v^0 d v \\\therefore E \cdot L &=v \\L &=[(v / L) v / m] \hat{i}\end{aligned}](https://tex.z-dn.net/?f=%5Cbegin%7Baligned%7D%26-E%20%5Cint_0%5EL%20d%20x%3D%5Cint_v%5E0%20d%20v%20%5C%5C%5Ctherefore%20E%20%5Ccdot%20L%20%26%3Dv%20%5C%5CL%20%26%3D%5B%28v%20%2F%20L%29%20v%20%2F%20m%5D%20%5Chat%7Bi%7D%5Cend%7Baligned%7D)
In conclusion, the magnitude and direction of the electric field in the wire are given as
![L &=[(v / L) v / m]](https://tex.z-dn.net/?f=L%20%26%3D%5B%28v%20%2F%20L%29%20v%20%2F%20m%5D)
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