E ElectroNewby Member Oct 23, 2011 #1 A ball is thrown at 25m/s Find: a) The maximum height b) flight time (There's nothing more so I assume the initial height is 0 and the angle 90)
A ball is thrown at 25m/s Find: a) The maximum height b) flight time (There's nothing more so I assume the initial height is 0 and the angle 90)
R Ratchit Well-Known Member Oct 23, 2011 #2 ElectroNewby, For constant acceleration "g" = 9.8 m/sec² dV/dt = g Integrating gives V = gt+Vo, where Vo is the initial velocity. Since gravity points down, the up direction is negative. Plugging in the values, 0 = gt -25 ==> t = 25/9.8 = 2.55 sec to go up and the same to go down ds = Vdt = Vo*dt + gt*dt ===> s = Vo*t + gt²/2 + s1, where s1 = 0 Plugging in the values we get s = -25*2.55 + 9.8*2.55²/2 = -31.89 meters high Ratch Last edited: Oct 23, 2011
ElectroNewby, For constant acceleration "g" = 9.8 m/sec² dV/dt = g Integrating gives V = gt+Vo, where Vo is the initial velocity. Since gravity points down, the up direction is negative. Plugging in the values, 0 = gt -25 ==> t = 25/9.8 = 2.55 sec to go up and the same to go down ds = Vdt = Vo*dt + gt*dt ===> s = Vo*t + gt²/2 + s1, where s1 = 0 Plugging in the values we get s = -25*2.55 + 9.8*2.55²/2 = -31.89 meters high Ratch
E ElectroNewby Member Oct 23, 2011 #3 Thank you very much Rachit ! That 25/9.8 was my missing puzzle and I should hit myself because it's simple
Thank you very much Rachit ! That 25/9.8 was my missing puzzle and I should hit myself because it's simple
M MrAl Well-Known Member Most Helpful Member Oct 24, 2011 #4 ElectroNewby said: A ball is thrown at 25m/s Find: a) The maximum height b) flight time (There's nothing more so I assume the initial height is 0 and the angle 90) Click to expand... Hi, Are you sure they meant 90 degrees because that's straight up. It could be, but most of the time these problems start with some known angle LESS than 90 degrees like 45 degrees so the projectile sweeps out an arc. Last edited: Oct 24, 2011
ElectroNewby said: A ball is thrown at 25m/s Find: a) The maximum height b) flight time (There's nothing more so I assume the initial height is 0 and the angle 90) Click to expand... Hi, Are you sure they meant 90 degrees because that's straight up. It could be, but most of the time these problems start with some known angle LESS than 90 degrees like 45 degrees so the projectile sweeps out an arc.