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1. Use the following information to answer parts a-h. A 13.6 kg shelf is held 1.50 m above the ground for 25.0 3 while it is screwed in to the wall. a] What is me potenh'al energiir of the shelf with respect to me ground? ill b] How much work is done on the shelf in this lime? {ll 2. Use the following information to answer parts ah. A student and her bicycle have a combined mass of 75.0 kg. She accelerates from rest to a velocity of 5.75 this in 15.0 s. a} How much work has she done accelerating her bicycle? l2} 2 Physics 20: SUMMER Assignment 10 b) What is the kinetic energy of the bicycle system after the acceleration? (1) 3. Two people each exert a force of 300 N, pulling a car by separate ropes in the East direction. The first person pulls at an angle of 20.0* N of E, and the second person pulls at an angle of 20.0' S of E. Calculate the work done on the car by each worker if the car moves 0.50 m/s for 5.6 s. (5)Physics 20: SUMMER Assignment 10 4. You have an apple that you would like to weigh, but you don't have a scale. You do have a slinky and a quick internet search tells you that it has a spring constant of 10.0 N/m. You hang the apple from the slinky and measure that the slinky stretches 9.92 cm. What is the mass of the apple? (2) 5. A spring with a spring constant of 45.5 N/m is stretched so that it has 2.275 J of potential energy. How far was the spring stretched? (1) 6. Use the following information to answer the question below. In an experiment to test Hooke's Law, a student measures the displacement of a spring with varying masses. The student used the mass and the displacement to calculate the force exerted on the spring for each mass. They were then able to graph the force on the spring versus the displacement of the mass. What does the slope of the line of best fit on the student's graph represent? (1)