6) Joe throws a 0.15-kg rubber ball directly downward to the floor. The ball’s speed just before impact is 6.5 m/s and just after the impact is 3.5 m/s. If the ball is in contact with the floor for 0.025 s, what is the magnitude of the average force that the floor exerts on the ball during the time of contact? A. 133 N B. 60 N C. 30 N D. 18 N E. 3.0 N

Ok i am attempting to my niece attach a galvanized wire (like a tether for a dog) at the corner of two fences, making a tightwire if you will and we drilled a hole in a softball and she hits it. the ? and problem is that we can not get the wire taunt enough where it doesnt sag after hitting the ball once, and the wire sags and wobbbles. its a 15 ft rubber covered galvanized wire and one can adjust the length of the placing of the wire by having it make the corner of 2 fences become a it can be adjusted, however, with all our human strength and pliers we could not make it taunt as possible. is there anything other that attaching it to a car to do this. sorry abt the length but it would mean the world to my niece if i could solve this came up with the entire idea herself, and she is 14 and paid for the wire and did as much work as i did drilling a hole through a softball wide enough for attaching piece at each end of the wire that clips on to the fence. . any ideas welcome if serious. but awesome if it is a fact. much obliged. bucky bukowski buckman

The percent efficiency of a machine can never be 100% (or greater), because in the real world some energy is always converted into a. heat b. work c. input force d. output force

Which process is represented by the pv diagram? a. the isobaric process b. the isovolumetric process c. the isothermal process d. the adiabatic process