It is claimed that some professional baseball players can see which way the ball is spinning as it travels toward home plate. one way to judge this claim is to estimate the distance at which a batter can first hope to resolve two points on opposite sides of a baseball, which has a diameter of 0.0738 m.

(a) estimate this distance, assuming that the pupil of the eye has a diameter of 2.00 mm and the wavelength of the light is 550 nm in vacuum.
(b) considering that the distance between the pitcher’s mound and home plate is 18.4 m, can you rule out the claim based on your answer to part (a)?

4. if you were an astronaut on the moon, what would you experience? what would you see from your perspective?

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

Calculate the first and second velocities of the car with four washers attached to the pulley, using the formulas v1 = 0.25 m / t1 , and v2 = 0.25 m / (t2 – t1) where t1 and t2 are the average times the car took to reach the 0.25 and the 0.50 meter marks. record these velocities, to two decimal places, in table e.