8. A girl pushes a 20 kg block on a 3 m high ramp inclined at 109. What speed will the block have at the top if the girl pushes with a constant 50N force starting from the bottom of the ramp? a. 7.67 m/'s b. 12.0 m/s c. 5.24 m/s d. The girl must use more force to push. 9. A sail of 3 kg has a speed of 1 m/s [S]. If a 30 kg boy running 3 m/s [N] jumps onto the sail, what will be the final speed of the sail? a. 2.63 m/s b. 2.81 m/s c. 2.72 m/s d. 3.00 m/s 10. What potential difference is required to start a proton from one side of a parallel plate capacitor at rest, but have a speed of 2 000 m/'s on the other side? a. 5.69 x 10" V b. 2.09 x 10"- V c. 1.13 x 105 V d. 5.69 x 10-2 V 60 WWW 1 1. Find the voltage drop across the 4 ohm resistor. 603 a. 12V b. 4.8 V $ 150 c. 1.2 V d. 7.2 V 24 V 40 12. Two charges located at x = 0 cm and x = 10 cm each have a charge of +8 nC and -5 nc respectively. Where might the a -3 nC charge be located to experience no charge? a. x = 32.9 cm b. x = 5.07 cm c. x = 18.9 cm d. x = 25.9 cm 13. What is the charge on a 0.50 g oil drop that is at rest in a parallel plate capacitor exerting an electric field of 3000 V/m [up]? a. 1.63 x 10-3 C b. 1.02 x 1013 C c. 1.02 x 1016 C d. 1.63 x 106 C 14. When the switch is closed, the current on the right coil of wire will flow: a. from - to + b. from + to - c. current will not flow d. cannot be determined 15. An electron is travelling 300 m/s [E] in a uniform magnetic field pointing inward with a magnitude of 3T. What is the force on this electron? a. 1.44 x 10- N [down] b. 1.44 x 10- N [up] C. ON d. 900 N [ down]16. Two parallel wires, each 3 m long, repel each other with 1614 of force. If the two wires have 111A of current owing, determine the distance between the two wires. a. 1133 m h. 6.66 x llll'Er n1 c.1166m d. 3.63 it 164m ) 1?. Two speakers are spaced 3.11m apart in the diagram as follows. What frequencies should the speakers emit to hear nothing at the marked point so In 4.6m away from one of the speakers as shown in the diagram? Assmne 1 the speed of\" sound is 343 mts. ) _ a. 36 Hz b. 129 Hz ) c. 1'12 Hz d. 215 H: \"In: 13. A douhle-slit interferenee pattern is created by two narrow slits spaced {1.26 mm apart. The distance between the rst and h minimum on a screen 61] cm behind the slits is 6.1] mm. What is the wavelength used in this experiment? a. 125 nm b. 2511 nm e. 1'51} nm d. 5111) nm 19. A lighthulh sits at the bottom of a 3.11 m deep swimming pool. What is the diameter of the circle of light seen from above in the air? The index of refraction oF water is 1.33. a. 1.11m b. 3.42m c.6134 m d. 13.63 It]. A rocket travels at a constant speed of tilde relative to the solar system. If a person on Earth measures the Satum-sun distance to be 1.43 x Ilium, what is the Samrn-sun distance as measured in the rocket's reference frame\";I a. 115 it It)\" or 13.1.43 it III}!12 or 6.3.121: ltl11 m d. 6.23 it It)11 n1