BackNear the surface of the Earth there is an electric field of about 150 V/m which points downward. Two identical balls with mass m = 0.550 kg are dropped from a height of 2.00 m, but one of the balls is positively charged with q₁ = 650 μC, and the second is negatively charged with q₂ = -650 μC. Use conservation of energy to determine the difference in the speeds of the two balls when they hit the ground. (Neglect air resistance.)
One possible form for the potential energy (U) of a diatomic molecule (Fig. 40–8) is called the Morse Potential:
(a) Show that r0 represents the equilibrium distance and U0 the dissociation energy.
What is the electric potential energy of the group of charges in FIGURE EX25.5?
A simple picture of an H₂ molecule sharing two electrons is shown in Fig. 40–56. We assume the electrons are symmetrically located between the two protons, which are separated by r0 = 0.074 nm. Make a graph of U in eV as a function of d in nm.
A small metal sphere, carrying a net charge of μC, is held in a stationary position by insulating supports. A second small metal sphere, with a net charge of μC and mass g, is projected toward . When the two spheres are m apart, , is moving toward with speed m/s (Fig. E). Assume that the two spheres can be treated as point charges. You can ignore the force of gravity. What is the speed of when the spheres are m apart?
(II) An electron starting from rest acquires 4.8 keV of kinetic energy in moving from point A to point B. How much kinetic energy would a proton acquire, starting from rest at B and moving to point A?
FIGURE P25.72 shows a thin rod with charge Q that has been bent into a semicircle of radius R. Find an expression for the electric potential at the center.
You are given the equation(s) used to solve a problem. Finish the solution of the problem: (9.0×109Nm2/C2)q₁q₂/0.030m =90×10−6J; q₁+q₂=40nC.
Electrodes of area A are spaced distance d apart to form a parallel-plate capacitor. The electrodes are charged to ±q. What is the infinitesimal increase in electric potential energy dU if an infinitesimal amount of charge dq is moved from the negative electrode to the positive electrode?
INT The surface charge density on an infinite charged plane is −2.0×10−6 C/m2. A proton is shot straight away from the plane at 2.0×106 m/s. How far does the proton travel before reaching its turning point?
Two identical +5.5 μC point charges are initially spaced 8.5 cm from each other. If they are released at the same instant from rest, how fast will they be moving when they are very far away from each other? Assume they have identical masses of 1.0 mg.
A manufacturer claims that a carpet will not generate more than 6.0 kV of static electricity. What magnitude of charge would have to be transferred between a carpet and a shoe for there to be a 6.0-kV potential difference between the shoe and the carpet? Approximate the area of the shoe and assume the shoe and carpet are large sheets of charge separated by a small distance d = 1.0 mm.
FIGURE P25.67 shows two uniformly charged spheres. What is the potential difference between points 1 and 2? Which point is at the higher potential? Hint: The potential at any point is the superposition of the potentials due to all charges.