. . . X Unit C: Section 3 Assignment C3: Part B 4 3. A toy uses a spring to shoot an arrow with a suction cup on the end. The toy shoots a 34.2 g arrow and gives it a speed of 5.50 m/s. If the efficiency of the toy is 69.0%, how much elastic potential energy was stored in the spring? Show all your work. Arrow with suction cup. . . X Total 15 Lesson 10: Efficiency Calculations 3 1 . A Bluetooth speaker used 573 J of energy while playing music. If it produces 356 J of sound energy, what is the efficiency of the speaker in transforming electrical energy into sound energy? Show all your work. Wireless Bluetooth speaker 3 2. A 150 W driveway light produces 9.3 x 10" J of light energy over a 4.0 h period. If the light uses 2.06 x 10 J of energy in the 4.0 h, then what is its efficiency? Show all your work. Electric driveway lightA cyclist is standing still at the top of a hiil and then begins to coast down the hill. The mass of the cyclist and bicycle is 64 kg total. The cyclist's gravitational potential energy is converted into kinetic energy with an efficiency of 52%. What is her speed when she reaches a point that is a vertical distance of 10 m lower than the point at which she started? Show all your work. Younggirln'dingbicycleonhill