IEW 9:23 & A 5 MECHANICS Il cHAPTER 5 PRACTICE PASSAGE ice is playing with her little brother Jeff at an ice skating rink (hat i$ entirely flat except for a ramp at one end that is at an upW\""d incline of 30 degrees. Alice is pushing Jeff on a little (oboggan that has blades on the bottom, so it glides along the surface of the ice without the effects of friction. Alice has a mass of 60 kg, Jeff has a mass of 28 kg and the mass of the {oboggan is2 kg. Alice is pushing Jeff around the rink and decides that she wants {0 push him right up until the incline, then let go and see how far up the incline he goes. They start from rest 10 meters from {he incline and she pushes him with a force that varies with the distance (Figure 1). Jeff goes specding up the incline with a velocity of 2 m/s, travels a certain distance and then comes speeding down. At the bottom of the incline, Jeff's toboggan collides with Alice and the two of them travel across the ice. d (m) Figure 1 Graph of force vs. distance Alice and Jeff keep sliding on the ice until the toboggan crashes ino the end of the rink, One of the blades on the bottom of the toboggan has come loose in the crash and it no longer glides Ef!'unlessly on the ice. Alice once again pushes Jeff with a force Biven by Figure 1 and lets go just as they reach the incline. This time Jeff (ravels 10 centimeters less up the incline than he did before the toboggan broke. 05 work_ke.pdf 1. A) B) ) D) A) B) C) D) w A) B) ) D) A) B) ) D) QN =l 82%m @ : \"+ . i {ll} How much work does Alice do from the moment she begins to push Jeff 10 m from the incline until she lets go just before the incline? 6071 751 0l There is not enough information to answer the question, The first time Jeff goes up the incline, what distance along the incline does the toboggan travel before it comes to rest? 02m 03m 0.4m 0.5m Assuming that the collision between Jeff and Alice at the bottom of the incline is perfectly inelastic, this tells us that: I. kinetic energy is conserved. II. momentum is conserved. 1II. total velocity before and after the collision is the same. Tonly 11 only Tand ITonly [ 11, and [11 Imagine that instead of Alice jumping on the toboggan during the collision, they \"bounce off of one another in a perfectly elastic collision and they both speed off in different directions. If Jeff speeds back up the incline with a velocity of 2/3 m/s, with what speed is Alice moving away from the incline? 1/3 m/s 2/3 m/s 1 m/s 4/3 m/s | 171 Once the toboggan has broken, if Jeff goes up the incline with the same initial velocity v as he did the first time, how much energy has been lost? A) B) O D) 1.0J 1.51 10 15) I O MCAT PHYSICS AND MATH REVIEy 7. If Jeff brought his friend Jeremy out to play with hing and Alice pushes both of them from rest on the t with the same force as given in Figure 1, how would iy, distance they travel up the incline and their initial velogj change from when just Jeff was being pushed (ignm',,! friction)? A) The velocity would be greater and they would go further B) The velocity would be greater and they would go less fay