A parallel beam of light makes an angle 30º with the surface of a glass plate having refractive index of 1.50. (a) What is the angle between the refracted beam and the surface of the glass? (b) What should be the angle of incidence φ with this plate for the angle of refraction φ/2 ?

An athlete swings a ball, connected to the end of a chain, in a horizontal circle. the athlete is able to rotate the ball at the rate of 8.13 rev/s when the length of the chain is 0.600 m. when he increases the length to 0.900 m, he is able to rotate the ball only 6.04 rev/s. (a) which rate of rotation gives the greater speed for the ball? 6.04 rev/s 8.13 rev/s (b) what is the centripetal acceleration of the ball at 8.13 rev/s? m/s2 (c) what is the centripetal acceleration at 6.04 rev/s? m/s2