recitation01-solutions

recitation01-solutions - Physics 2760 Recitation Sept 2nd,...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Physics 2760 Recitation Sept 2nd, 2008 1. Two small beads having positive charges 3q and q are fixed at the opposite ends of a horizontal insulating rod extending from the origin to the point x = d. A third small charged bead is free to slide on the rod. At what position x is the third bead in equilibrium? 2. Two point charges are separated by 25.0 cm (see the figure). A) Find the magnitude and direction of the net electric field these charges produce at point A. B) Find the magnitude and direction of the net electric field these charges produce at point B. C) What would be the magnitude and direction of the electric force this combination of charges would produce on a proton at A? mp = 1.67 x 10‐27 kg qp = 1.6 x 10‐19 C k = 9 x 109 Nm2/C2 3. A uniform electric field exists in the region between two oppositely charged plane parallel plates. A proton is released from rest at the surface of the positively charged plate and strikes the surface of the opposite plate, 1.60 cm distant from the first, in a time interval of 1.5 × 10−6 s. A) Find the magnitude of the electric field. B) Find the speed of the proton when it strikes the negatively charged plate. 4. Two tiny balls of mass m carry equal but opposite charges of magnitude q. They are tied to the same ceiling hook by light strings of length L. When a horizontal uniform electric field E is turned on, the balls hang with an angle θ between the strings (see the figure). A) Which ball (the right or the left) is positive, and which is negative? B) Find the angle θ between the strings in terms of E, q, m, and g. C) As the electric field is gradually increased in strength, what does your result from part (b) give for the largest possible angle θ? 5. An electron is projected with an initial speed v0 = 1.90×106 m/s into the uniform field between the parallel plates in the figure. Assume that the field between the plates is uniform and directed vertically downward, and that the field outside the plates is zero. The electron enters the field at a point midway between the plates. If the electron just misses the upper plate as it emerges from the field, find the magnitude of the electric field. ...
View Full Document

Ask a homework question - tutors are online