# PHYS 120 Lecture Notes - Lecture 5: Conditionality, Tennis Ball, Friction

## Document Summary

A single mass m1 = 3. 3 kg hangs from a spring in a motionless elevator. Now, three masses m1 = 3. 3 kg, m2 = 9. 9 kg, and m3 = 6. 6 kg hang from three identical springs in a motionless elevator. The springs all have the same spring constant that you just calculated above. Finally, the elevator is moving downward with a velocity of v = -2. 1 m/s and also accelerating downward at an acceleration of a = - 2. 6m/s2. Rank the distances the springs are extended from their unstretched lengths: a. b. c. What is the distance the middle spring is extended from its unstretched length: forces and free-body diagrams page 1. In a loop-the-loop ride, a car goes around a vertical, circular loop at a constant speed. The car has a mass m = 220 kg and moves with speed v = 15. 91 m/s. The loop-the-loop has a radius of r = 10. 6 m.