# Tutor profile: David H.

## Questions

### Subject: Physics (Electricity and Magnetism)

what is the difference between electric fields and an electric force?

both of these phenomenon are due to charged particles. All charged particle produce an electric field around them. These fields are described by the following equation: kQ/r^2, where k is a constant, Q is the magnitude of the charge on the particle, and r is the distance away from the particle. These fields want to pull of objects of opposite charge and push away charges of the same kind. The push/pull action is due to the introduction of another particle into the electric field. This is represented by the electric force equation: kQq/r^2, the small q in this equation represents the additional charged particle. all charged particle produce an electric field, however an electric force is created when two charged particle and their associated field interact with one another.

### Subject: Physics

Please explain what centripetal force is, and how it works.

Centripetal force is the force that is generated by an object when traveling in a circular motion. Imagine you are swinging a ball attached to a string in a circular motion. The ball is pushed to the end of the string and you can feel the ball exerting a force on your hand, trying to pull the ball even further away from you. The force responsible for this phenomenon is centripetal force.

### Subject: Calculus

What is the difference between a closed and open integral?

A closed integral has limits placed above and below the integration symbol, where as the open integral does not have limits. When solving the integral, an open integral is left in terms of the variable (usually x). where as with the closed integral you would integrate the equation in term of the variable and then you would plug the upper limit into the integrated equation and solve for the numerical value, you will then plug the lower limit into the integrated equation and solve for that numerical value. Next you take the difference between those numerical values to find the answer.

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