The electron gun in an old TV picture tube accelerates electrons between two parallel plates 1.2 cm apart with a 26 kV potential difference between them. The electrons enter through a small hole in the negative plate, accelerate, then exit through a small hole in the positive plate. Assume that the holes are small enough not to affect the electric field or potential. • Part A What is the electric field strength between the plates? Express your answer to two significant figures and include the appropriate units. ? E- Value Units Submit Reauest Answer • Part B With what speed does an electron exit the electron gun if its entry speed is close to zero? Note: The exit speed is so fast that we really need to use the theory of relativity to compute an accurate value. Your answer to part B is in the right range but a little too big. Express your answer to two significant figures and include the appropriate units. Vexit Value Units

Part B The total electron charge within a radius r equals the integral of p(ri) dV from ri = 0 to ri = r. Set up this integral (but don't solve yet), and use it to write an expression for the total charge (including the proton) within a sphere of radius r. > View Available Hint(s) -2r/a047r? dri. the expression for the total charge is The expression for the electron's charge disturbed in the space is -q(r)sphere = Jo Qencl = 0. %3D Пао3 -2r/a04Tr? dri. the expression for the total charge is The expression for the electron's charge disturbed in the space is -q(r)sphere = Jo Qenel = Qproton - q(r)sphere- The expression for the electron's charge disturbed in the space is -q(r)sphere = ( -2r/ao 47TT? dri, the expression for the total charge is Qencl = Qproton - q(r)phere- e-2r/a04rr? drı, the expression for the total charge is The expression for the electron's charge disturbed in the space is -q(r)sphere = Jo - ( Qenel = Qproton +q(r)sphere- Submit Previous Answers Correct

Part A Two 2.0cm x 2.0cm metal electrodes are spaced 1.4 mm apart and connected by wires to the terminals of a 9.0 V battery. What is the charge on each electrode? Express your answer with the appropriate units. • View Available Hint(s) HÁ Value Units Submit ▼ Part B What is the potential difference between electrodes? Express your answer with the appropriate units. • View Available Hint(s) HÀ AV = Value Units

A uniform electric field exists in the region between two oppositely charged plane parallel plates. An electron is released from rest at the surface of the negatively charged plate and strikes the surface of the opposite plate, 3.80 cm distant from the first, in a time interval of 1.50×108 s For related problem-solving tips and strategies, you may want to view a Video Tutor Solution of Accelerating an electron Part A Find the magnitude of this electric field. Express your answer in newtons per coulomb. 1957 ΑΣΦΑ E- Submit Part B Request Answer Find the speed of the electron when it strikes the second plate. Express your answer in meters per second. VE ΑΣΦ| UM ? N/C m/s