Tania releases a javelin 1.2 meters above the ground with an initial vertical velocity of 20 meters per second. how long will it take the javelin to hit the ground? - 16t2 + 20t + 1.2 = 0 - 4.9t2 + 20t + 1.2 = 0 - 4.9t2 + 20t = 1.2 - 4.9t2 + 1.2t + 20 = 0

This is an example of free fall;

For free fall the gravitational acceleration is - 9.8 m/s²

From the equation;

S = ut - 1/2gt², where S is the height above the ground, U is the initial vertical velocity, t is the time taken.

Therefore;

1.2 = 20t - 1/2 (9.8) t²

1.2 = 20t - 4.9t²

Thus; the equation is - 4.9t² + 20t = 1.2, this is the appropriate answer.