# Lesson Worksheet: 2D Motion in Uniform Electric Fields Physics

In this worksheet, we will practice analyzing the motion of charged objects that move in arbitrary directions through uniform electric fields.

Q1:

A particle has a mass of and a charge of C. The particle is moving at a speed of 452 m/s perpendicularly to the uniform electric field when it enters the field, as shown in the diagram. The particle moves 8.62 mm in the direction of the field before it exits it. What is the strength of the electric field?

Q2:

A positively charged particle with a charge of 2.45 µC and a mass of kg moves perpendicularly to a uniform electric field, as shown in the diagram. Find the speed of the particle at the point where it leaves the field. Answer to two significant figures.

Q3:

A pair of oppositely charged parallel plates separated from each other by a 10 m distance have a potential difference of 20 V across them due to the uniform electric field between them. A positively charged object is propelled into the field perpendicular to its direction, starting from the positively charged plate and crossing the field completely in the time it takes the object to reach the negatively charged plate, which is 0.64 s. The object is retrieved, and the plates are moved so that they are 5.0 m apart. The object is then propelled into the field, and when it crosses between the plates, it is displaced the same distance perpendicular to the direction of the field as the first time it passed between the plates. How much less time is taken for the object to complete its motion if the plates are 5 m apart?

Q4:

A particle has a mass of kg and a charge of C. The particle is moving diagonally toward a uniform electric field, as shown in the diagram. The particle exits the electric field traveling perpendicularly to it after moving 1.25 mm in the opposite direction to the field.

What is the strength of the electric field?

• A N/C
• B N/C
• C N/C
• D N/C
• E N/C

What is the power supplied to the particle by the electric field?

Q5:

A particle with a charge of 1.02 µC has a kinetic energy of 0.422 µJ when it enters a region of a uniform electric field. The particle enters the field from below, as shown in the diagram. A short time later, the particle exits the top of the electric field, having meanwhile traveled 115 cm in the direction of the field.

What is the kinetic energy of the particle when it leaves the electric field?

When the particle exits the electric field, is the angle between the particle’s direction of motion and the direction of the field greater than, less than, or equal to the angle between the particle’s direction of motion when it enters the field and the direction of the field?

• AGreater
• BLess
• CEqual

Q6:

A particle has a mass of kg and a charge of 10.2 µC. The particle is moving at a speed of 216 m/s perpendicularly to the uniform electric field when it enters the field, as shown in the diagram. What is the speed of the particle in the direction of the field at the point that the particle exits the field?

Q7:

An object of mass 2.5 kg has a charge of 0.75 C. The object is thrown horizontally into a vertically upward-directed uniform electric field through which it travels for 2.25 m at an average horizontal speed of 15 cm/s. The object descends 5.5 m while traveling through the electric field. Find the electric field strength.

Q8:

A positively charged particle with a charge of 111 nC and a mass of kg moves perpendicularly to a uniform electric field, passing through the field in a time of 0.229 ms, as shown in the diagram. Find the distance that the particle moves in the direction of the field while it is within it. Give your answer to 2 significant figures.

Q9:

A particle has a charge of C and a mass of 0.44 µg. The particle moves with a speed , traveling perpendicularly to a uniform electric field between two charged flat surfaces as shown in the diagram. When the particle enters the electric field region, after traveling a distance in the direction of the field, its speed parallel to the direction of the field is . The potential across is 12 V. Find the kinetic energy of the particle before it enters the electric field. Answer to two significant figures.

Q10:

A negatively charged particle with a charge of is initially moving perpendicularly to a uniform electric field at a speed , as shown in the diagram. The colored arcs represent possible paths followed by the particle. For each of the possible paths followed, the time interval in which the particle travels from the start of the path to the end of the path is the same.

Which color arcs represent the particle having the same value of ?

• AGreen and orange
• BOrange and pink
• CPink and green

Which color arcs represent the particle having the same value of ?

• AGreen and pink
• BPink and orange
• COrange and green