In a race, usain bolt accelerates at 1.99m/s^2 for the first 60.0m, then decelerates at -0.266m/s^2 for the final 40.0m. what was his final velocity? (unit = m/s)

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

Astone dropped into a well is heard to strike the water after 8seconds. find the depth of the well if the velocity of sound is 350m/s

Marvin records scientific data about lake superior. for which property has marvin forgotten to use an si unit of measurement? shore length high temperature low temperature annual precipitation