The net force on the charge at the origin is -1.2×10-8
<u>Explanation:</u>
Solving the problem,
- Draw the x-axis and the locations of the given three charges.
- The forces applied on the charge at the origin and there are two of them, and since all the changes are positive, all the forces are repulsive.
- we have the formula, F = kq1Q/r².
- F1 = kq1Q/r²1 = (9.0*109Nm²/C²)(2.2*10^-9C)(3.5*10^-9C)/(1.5m)² = 31*10-9N = 3.1*10-8N. F1 points to the right (+x direction).
- F2 = kq2Q/r²2 = (9.0*109Nm²/C²)(5.4*10^-9C)(3.5*10^-9C)/(2.0m)² = 43*10^-9N = 4.3*10^-8N.
- F2 points to the left (-x direction).
- To find the net force we have to subtract the force F1 and force F2 .
- The net force is F(origin) = F1 - F2 = -1.2×10-8N.
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The gravitational field strength is approximately equal to 10 N.
<u>Explanation:</u>
Gravitational field strength is the measure of gravitational force acting on any object placed on the surface of the planet. Generally, the mass of the object is considered as 1 kg.
So the gravitational field strength will be equal to the gravitational force acting on the object.
The formula for gravitational field strength is

Here g is the gravitational field strength, m is the mass of the object placed on the surface and F is the gravitational force acting on the object.
Since, the mass of any object placed on the surface of earth will be negligible compared to the mass of Earth, so the mass of the object is considered as 1 kg.
Then the g = F
And 
Here G is the gravitational constant, M is the mass of Earth and m is the mass of the object placed on the surface, while r is the radius of the Earth.


So, the gravitational field strength is approximately equal to 10 N.
1 and 4 are tire.
2 and 3 are not.
Newton's law of universal gravitation states that a particle attracts every other particle in the universe using a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers
You can't. Velocity and acceleration measure two different things, so their units are incompatible. It's like asking, "How many meters does this book weigh?"
Maybe you mean "find" acceleration using given velocities, or a velocity function?