Potential and Force

As a proton moves in the direction the electric field lines

• it is moving from low potential to high potential and gaining electric potential energy.

• it is moving from low potential to high potential and losing electric potential energy.

• it is moving from high potential to low potential and gaining electric potential energy.

• it is moving from high potential to low potential and losing electric potential energy.

A proton is accelerated from rest through a potential difference V0 and gains a speed v0. If it were accelerated instead through a potential difference of 2V0, what speed would it gain?

• 8v0

• 4v0

• 2v0

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-2

Four charged particles (two having a charge +Q and two having a charge -Q) are arranged in the xy-plane, as shown in the figure. These particles are all equidistant from the origin. The electric potential (relative to infinity) at point P on the z-axis due to these particles, is

• zero

• positive

• negative

• impossible to tell

Tags

NGSS.HS-PS2-4

A tiny particle with charge + 5.0 μC is initially moving at 55 m/s. It is then accelerated through a potential difference of 500 V. How much kinetic energy does this particle gain during the period of acceleration?

• 1.0 × 10^4 J

• 2.5 × 10^-3 J

• 100J

• 2500J

Tags

NGSS.HS-PS3-1

How much work must we do on an electron to move it from point A, which is at a potential of +50V, to point B, which is at a potential of -50 V, along the semicircular path shown in the figure? Assume the system is isolated from outside forces. (e = 1.60 × 10-19 C)

• 1.6J

• 1.6 x 10^-17 J

• -1.60 x 10^-17 J

• -1.6J

Tags

NGSS.HS-PS2-4

NGSS.HS-PS3-1

A negatively-charged rod is brought close to (but does not touch) two neutral spheres that are in contact with each other but insulated from the ground. If the two spheres are then separated, what kind of charge will be on the spheres?

• The sphere near the charged rod becomes positive and the other one becomes negative.

• The sphere near the charged rod becomes negative and the other one becomes positive.

• The spheres do not get any charge.

• Both spheres become negative.

The zirconium nucleus contains 40 protons, and an electron is 1.0 nm from the nucleus. What is the electric force on the electron due to the nucleus? ( e = 1.60 × 10-19 C, k = 1/4πε0 = 9.0 × 109 N ∙ m2/C2)

• 3.7 nN

• 1000 C

• 6.8 nN

• 9.2 nN

Tags

NGSS.HS-PS2-4

Two point charges each experience a 1-N electrostatic force when they are 2 cm apart. If they are moved to a new separation of 8 cm, what is the magnitude of the electric force on each of them?

• 1/16

• 1/2

• 1/4

• 1/8

Tags

NGSS.HS-PS2-4