the height of an object after t seconds is given by f(t)=-5t^2+20t (a) find the height of the object after 2 seconds, and include the correct units with your answer. (b) find the average (vertical) velocity of the object on the time interval [0,2]. show your work, include the correct units, and. circle your final answer. (c) find the instantaneous velocity at t=2

Me with this assignment ! i only partially understand, so explain. also it's a work sample. at the championship bike race, steve and paula were fighting for first place. steve was 175 feet ahead of paula and had only 300 feet left to go. he was very tired and was going only 9 feet per second. paula was desperate to catch up and was going 15 feet per second. who won the bike race and by how far did she/he win?