Question

A proton and an electron are released from rest, with only the electrostatic force acting. Which of the following statements must be true about them as they move toward each other? (There could be more than one correct choice.) Check all that apply. Check all that apply. Their electric potential energy keeps increasing. Their electric potential energy keeps decreasing. Their kinetic energy keeps decreasing. Their kinetic energy keeps increasing. Their acceleration keeps decreasing.

Answer 1

Answer:

their electrical potential energy decreases. True, because of the negative sign as the distance decreases, it becomes more negative.

The kinetic energy increases. True, the force is attractive as the distance decreases the force increases, so acceleration and therefore the speed

Explanation:

The only force between the proton and the electron is electric

      Fe = k q1q2 / r2

      Fe = - k e2 / r2

We can see that it is an attractive force (negative sign)

The electric power energy is

       U = k q1 q2 / r

       U = -k e2 / r

 

The kinetic energy is

       K = ½ m v2

With the expressions for each term we can analyze the sentences :

Their electric potential energy increases. False,

their electrical potential energy decreases. True, because of the negative sign as the distance decreases, it becomes more negative.

The kinetic energy increases. True, the force is attractive as the distance decreases the force increases, so acceleration and therefore the speed

Kinetic energy decreases False

The acceleration decreases.  False, as the force increases so does the acceleration