Homework phys 101 gmu solution
Content
Physics 2 E-Home Work 1
I. Electric Potential of a Constant E field.
A parallel plate capacitor sets up a constant electric field |E| = 14.0E4 V/m
between plates separated by a distance of d = 0.75 cm. An electron is positioned
on the negative plate initially and allowed to move freely from a position of rest.
Neglecting gravity answer the following questions.
+
+
+
+
E
d
−
−
−
−
−
1. What is the magnitude of the potential difference |ΔV| between the plates?
2. Does the electron accelerate? If so in what direction does the electron
accelerate?
3. What is the value of the electric potential energy of the electron when it is
positioned at the negative plate
4. The electron will be accelerated toward the positive plate. What will be the
magnitude of the electric potential energy when it reaches the positive plate?
5. What is the value of the kinetic energy when the electron reaches the anode?
6. What is the speed of the electron when it reaches the anode?
7. What is the magnitude of the acceleration of the electron?
8. What is the magnitude of the electric force on the electron as it moves from
cathode to anode?
9. Use Newton’s Second Law and kinematic equations to determine the speed of
the electron when it hits the positive plate. How does this compare to the speed
calculated previously with conservation of energy?
II.
Coulomb’s Law
X
−q1
+
−q2
L = 0.75 cm
Consider the charge configuration above. q1 = -3.00 µC and q2 = -5.00 µC. A +2.00 mC is
placed between the tow negative charges.
10. Draw in the directions of the respective forces on the positive charge due to the tow
negative charges.
11. Apply Newton’s Second Law to determine the point x where the net force is zero ΣF = 0.
12. What is the magnitude of the Electric field at this point? (Hint: Consider the definition of
the electric field)
Answer Sheet
Name_________________________________
1. ___________________________
2. ___________________________
3. ___________________________
4. ___________________________
5. ___________________________
6. ___________________________
7. ___________________________
8. ___________________________
9. ___________________________
10. ___________________________
11. ___________________________
12. ___________________________
_______________________
I. Electric Potential of a Constant E field.
A parallel plate capacitor sets up a constant electric field |E| = 14.0E4 V/m
between plates separated by a distance of d = 0.75 cm. An electron is positioned
on the negative plate initially and allowed to move freely from a position of rest.
Neglecting gravity answer the following questions.
+
+
+
+
E
d
−
−
−
−
−
1. What is the magnitude of the potential difference |ΔV| between the plates?
2. Does the electron accelerate? If so in what direction does the electron
accelerate?
3. What is the value of the electric potential energy of the electron when it is
positioned at the negative plate
4. The electron will be accelerated toward the positive plate. What will be the
magnitude of the electric potential energy when it reaches the positive plate?
5. What is the value of the kinetic energy when the electron reaches the anode?
6. What is the speed of the electron when it reaches the anode?
7. What is the magnitude of the acceleration of the electron?
8. What is the magnitude of the electric force on the electron as it moves from
cathode to anode?
9. Use Newton’s Second Law and kinematic equations to determine the speed of
the electron when it hits the positive plate. How does this compare to the speed
calculated previously with conservation of energy?
II.
Coulomb’s Law
X
−q1
+
−q2
L = 0.75 cm
Consider the charge configuration above. q1 = -3.00 µC and q2 = -5.00 µC. A +2.00 mC is
placed between the tow negative charges.
10. Draw in the directions of the respective forces on the positive charge due to the tow
negative charges.
11. Apply Newton’s Second Law to determine the point x where the net force is zero ΣF = 0.
12. What is the magnitude of the Electric field at this point? (Hint: Consider the definition of
the electric field)
Answer Sheet
Name_________________________________
1. ___________________________
2. ___________________________
3. ___________________________
4. ___________________________
5. ___________________________
6. ___________________________
7. ___________________________
8. ___________________________
9. ___________________________
10. ___________________________
11. ___________________________
12. ___________________________
_______________________
