Question 206638
well first use the equation...
- {{{Vf = Vi - gt}}} (where Vf = final velocity, Vi = initial velocity)
and solve for t
Since the velocity is zero at the peak that's our final velocity
- {{{0 = 245 - (9.81)(t)}}}
- {{{0-245 = 245-245-9.81t}}}
- {{{-245 = -9.81t}}}
- {{{-245/-9.81 = (-9.81t)/-9.81}}}
- {{{-245/-9.81 = (cross(-9.81)t)/cross(-9.81)}}}
- {{{24.97 = t}}}
- so the projectile took 24.97 seconds to reach the peak
To find how long before it hit the ground simply double the time it took to reach the peak so...
{{{24.97*2 = 49.94}}}
So the projectile took 49.94 seconds to return to the ground