Answer:
c > √(2ab)
Explanation:
In this exercise we are asked to find the condition for c in such a way that the results have been real
The given equation is
½ a t² - c t + b = 0
we can see that this is a quadratic equation whose solution is
t = [c ±√(c² - 4 (½ a) b)] / 2
for the results to be real, the square root must be real, so the radicand must be greater than zero
c² -2a b > 0
c > √(2ab)
Answer:
Sunscreen is like a shield, you would want a better shield to protect you than a weak one so companies try to make their sunscreen better than the rest.
The work-energy theorem states that the change in kinetic energy of the particle is equal to the work done on the particle:

The work done on the particle is the integral of the force on dx:

So, this corresponds to the change in kinetic energy of the particle.
To solve this problem we will apply the concept related to the magnetic dipole moment that is defined as the product between the current and the object area. In our case we have the radius so we will get the area, which would be



Once the area is obtained, it is possible to calculate the magnetic dipole moment considering the previously given definition:



Therefore the magnetic dipole moment is 
Answer:
Please see below as the answers are self-explanatory
Explanation:
a)
- A electric field line is an imaginary line, which has the property that the electric field vector is tangent to it at any point. It starts from positive charges (since the electric field by convention it has the direction of the trajectory that would take a positive test charge, so it always goes away from positive charges) and ends in negative charges.
b)
- Since the potential difference between two points represents the work per unit charge needed for a charge to move between these points, a equipotential surface is the one over which it is not needed to do work to move a charge from any point on the surface to any other point, which means that all points are at the same potential.
c)
- Equipotential surfaces are not necessarily physical surfaces, they can be defined in vaccum for instance.
- As an example, any spherical surface concentric with a point charge, is an equipotential surface, and it can be a real surface or a fictitious one.