Problema Solution
The distance, s, in feet, that an object falls (neglecting air resistance) in t seconds is given by s=vt=16t2, where v is the initial speed of the object in feet per second. An object is released from the top of a building 910ft high. The initial speed is the 18 ft/s, air resistance is neglected. How many seconds later wih the object hit the ground?
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sol.
distance travelled by the object is given by the formula
s= vt + 16t^2
let at time t secs the object hits the ground. now for the object to hit the ground it has to travel the whole length of the building i.e. 910ft
=> 910 = 18t + 16t^2
=>16t^2 +18t -910 =0
=> t = 7 secs
therefore, 7secs after releasing the ball from the top of the building it will reach tha ground