<span>According to the Biot-Savart law, the magnetic field produced by a moving charge will be zero at a point in back of. The correct option among all the options that are given in the question is the second option or option "b". I hope that this answer has actually come to your help.</span>
Explanation:
We know that in a projectile motion time of flight

So, we can notice that time of flight is dependent only on height from which the projectile is thrown. The more the height the more will be time of flight. So, if we increase the height the time of flight of the projectile will certainly increase.
Answer:
The magnitude of the electric field is 1475000 N/C and the direction of the electric field is toward north.
Explanation:
Given that,
Electric force 
The direction of force is toward the north.
We need to calculate the magnitude of the electric field
Using formula of electric field

Where, f = electric force
q = charge
Put the value into the formula


The direction of the electric field is toward the direction of the force so,
The direction of the electric field is toward north.
Hence, The magnitude of the electric field is 1475000 N/C and the direction of the electric field is toward north.
Answer:
The distance of dog from the shore is 3.97 m
Explanation:
given,
mass of the dog = 3.1 Kg
mass of the flatboat = 18 Kg
Distance from the shore = 6.1 m
dog moves on boat = 2.5 m
dog moves leftward and boat moves rightward.
If it's a frictionless system with no initial velocity, the center of mass doesn't move. Conservation of momentum, which = 0 in this case.
When dog move toward the shore a reactive force will act on the boat.

m_b i and m_d is mass of boat and mass of dog.
x_b and x_d is distance moved by the boat and the dog.

neglecting negative sign
x_b + x_d = 2.5




x_d = 2.133 m
The distance of dog from the shore is 6.1 – 2.133 = 3.97 m
The distance of dog from the shore is 3.97 m