Abaseball (radius = .0366 in, mass = .145 kg) is dropped from rest at the top of the empire state building (height = 1250
ft). calculate (a) the initial potential energy of the baseball, (b) its nal kinetic energy, and (c) the total energy dissipated by
the falling baseball by computing the hue integral of the force of air resistance along the baseball’s total distance of fall.
compare this last result to the difference between the baseballs initial potential energy and its nal kinetic energy. (hint: in
part (c) make approximations when evaluating the hyperbolic functions obtained in carrying out the line integral.)

Keneila is attempting to ski down a 20 m high friction free hill for the first time. she has a speed 10 m/s at the top. what is her kinetic energy when she is a the bottom, 20 m ? (a)2500 j (b)9800 j (c)12300 j (d)3100j (e)15000j

Find v(t), given acceleration a(t)=7j and initial velocity v(0)=k

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