how to calculate the tie when the initial velocity of and object (rock) is given ( 12m/s 42 degrees above the horizontal. The object land at the other side of say a moat at a level of 9.5 m below the initial level. Air resistance is negligible. What is the time of flight? (the answer given in the book is 2.4s) How do you get that answer, what formulas do you use?
4 answers
what is "tie"?
u = 12 cos 42 = 8.92 m/s the whole time
Vi = 12 sin 42 = 8.03
v = Vi - 9.81 t
h = 9.5 + Vi t - 4.9 t^2
0 = 9.5 + 8.03 t - 4.9 t^2
t = [ -8.03 +/- sqrt (8.03^2-4*-4.9*9.5)]/-9.81
t = [-8.03+/-sqrt(251) ]/-9.81
t = 2.43 s
Vi = 12 sin 42 = 8.03
v = Vi - 9.81 t
h = 9.5 + Vi t - 4.9 t^2
0 = 9.5 + 8.03 t - 4.9 t^2
t = [ -8.03 +/- sqrt (8.03^2-4*-4.9*9.5)]/-9.81
t = [-8.03+/-sqrt(251) ]/-9.81
t = 2.43 s
bruh rearranged the 0=9.5+8.035-4.9t^2 so people know what you are doing
8.03t^^