Physics 30S Final Exam Review-2.pdf

Physics 40S RRSD Final Exam – June 2005 Page 617. A car travels in a circle with a constant speed. The net force on the cara) is directed forward in the direction of travelb) is directed toward the center of the curvec) is zero because the car is not acceleratingd) is directed outwards from the center18. A 45.0-kilogram boy is riding a 15.0-kilogram bicycle with a speed of 8.00meters per second. What is the combined kinetic energy of the boy and thebicycle?a) 240.J b) 1440 Jc) 480. J d) 1920 J19. A 40.-kilogram student runs up a staircase to a floor that is 5.0 meters higherthan her starting point in 7.0 seconds. The student’s power output is3a) 29 W b) 1.4× 10 W4c) 280 W d) 1.4× 10 W20. You walk to class at a steady pace along a flat, horizontal path. Your backpackweighs 100 Newton’s and your trip is 500 meters long. How much work do youdo on your backpack?a) 0 joules b) 1/5 joulec) 50,000 joules d) 5 joules21. The work done in pushing a lawnmower 100 m with a force applied of 30 N atan angle which is 60° to the horizontal is:a) 300 J b) 3000Jc) 1000 J d) 1500 J22. Two objects attract each other with a force of gravity (Fg) of 36 N. If thedistance separating the objects is doubled and the mass of one of the objects isdoubled, then what is the new force of gravitational attraction?a) 48 N b) 27 Nc) 12 N d) 18 N23. An asteroid has a mass of 5.2 x 10 19 kg and a radius of 45 km. What is thevalue of "g" on it's surface?a) 3.8 m/s 2 b) 1.7 m/s 2c) 10.6 m/s 2 d) 0.89 m/s 2