HELP I NEED THIS ANSWERED AS FAST AS POSSIBLE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

15. You want to calculate the displacement of an object thrown over a bridge. Using -10 m/s2 for acceleration due to gravity, what would be the total displacement of the object if it took 8 seconds before hitting the water?

Respuesta :

Displacement is d  


Vf² = Vi² + 2 g d  


(-20²) = (+10²) + 2 (-9.8) d  


-19.6 d = 300  


d = -15.3 m  


negative means lower


time is t  


d = Vi t + 1/2 g t²



-15.3 = 10 t + (-4.9) t²



4.9 t² - 10 t -15.3 = 0  


t = 3.06 s

Hope this helps -John