7. A physical science text book has a mass of 12.2 kg a. What is the weight on the Earth?
b. What is the weight on Mars (g = 3.7 m/s?)
c. If the textbook weights 9.6 Newtons on Venus, What is the strength of gravity on Venus?

Consider a uniformly charged ring in the xy plane, centered at the origin. the ring has radius a and positive charge qdistributed evenly along its circumference. a)what is the direction of the electric field at any point on the z axis? . b)what is the magnitude of the electric field along the positive z axis? use k in your answer, where k=14πϵ0. d)the ball will oscillate along the z axis between z=d and z=−d in simple harmonic motion. what will be the angular frequency ω of these oscillations? use the approximation d≪a to simplify your calculation; that is, assume that d2+a2≈a2. express your answer in terms of given charges, dimensions, and constants