You throw a football straight up into the air with a speed of 12.2 m/s. How high does the ball go?

Question

jdoe0001 · Answer

well, if the speed is kept constant, 12.2m/s   then the football will just go off the atmosphere and off to space

anonymous · Answer

0.62 m
 		B.	3.2 m
 		C.	9.1 m
 		D.	7.6 m
Those are the options

jdoe0001 · Answer

$\bf \text{initial velocity}\
h = -4.9t^2+v_ot+h_o \qquad \text{in meters}\ \quad \
h_o=\textit{initial height, in this case, 0}\
v_o=\textit{initial velocity or speed, in this case 12.2}\ \quad \
h = -4.9t^2+v_ot+h_o \implies h = -4.9t^2+12.2t+0$

notice is a parabola, with a negative leading coefficient, thus is opening downwards, highest point is its vertex

you can find the vertex of a $\bf y=ax^2+bx+c$ equation at the coordinates of $\bf \left(-\cfrac{b}{2a}\quad ,\quad  c-\cfrac{b^2}{4a}\right)$

jdoe0001 · Answer

the height will be the y-coordinates of course

anonymous · Answer

Which one is the correct answer ?