SP212/3321&5521
Chapter 22 - Worksheet #3
Question 1: A point particle with mass m=2.50×10−4 kg and charge q=−3.50µC has an initial velocity of ~v0 =(200 m/s)î when it enters a region of space with a uniform electric field of
~
E=(2500
N/C)î. What is the particle’s speed 4.00 s after it entered this region?
v0 =200 m/s
q=−3.50µC
E=2500 N/C
Question 2: A point particle with mass m=2.50×10−4 kg and charge q=−3.50µC has an initial velocity of ~v0 =(200 m/s)î when it enters a region of space with a uniform electric field of
~
E=(2500
N/C)ĵ. What is the particle’s speed 4.00 s after it entered this region?
v0 =200 m/s
q=−3.50µC
E=2500 N/C
SP212/3321&5521
Chapter 22 - Worksheet #3
A dipole consists of two charges, of +2.50 mC and −2.50 mC, separated by a distance of
2.5×10−9 m. This dipole is placed in an electric field of strength E=5500 N/C. The dipole is
oriented as shown, with the dipole moment making a 60◦ angle with the field.
+1.25 mC
+
60◦
E=5500 N/C
−
−1.25 mC
Question 3: What is the magnitude of the instantaneous torque acting on the dipole? Is the torque
clockwise or counter-clockwise?
Question 4: The dipole is then rotated 180◦ so that the dipole moment now makes a 240◦ (or −60◦ )
angle with the electric field. What was the change in the potential energy of the dipole?