At 3:19 I posted a problem wrong. Should be Mona and Kashi are hiking in the mts. Stopped for lunch on a ledge 1000 ft above the valley. Kishi climbed to a ledge 20 ft above mona. Mona throws an apple up to Kishi, but she missed it. The equation h = - 16t2+ 30t + 1000 represents the height in ft of the apple t seconds after thrown. SO HOW long did it take for the apple to reach the ground? NEXT if it takes 3 seconds to react, will they have time to call down to hikers below. Assume sound travels about 1000 ft per sec

Question

At 3:19 I posted a problem wrong. Should be Mona and Kashi are hiking in the mts.  Stopped for lunch on a ledge 1000 ft above the valley. Kishi climbed to a ledge 20 ft above mona. Mona throws an apple up to Kishi, but she missed it. The equation h = - 16t2+ 30t + 1000 represents the height in ft of the apple  t seconds after thrown. SO HOW long did it take for the apple to reach the ground? NEXT if it takes 3 seconds to react, will they have time to call down to hikers below.  Assume sound travels about 1000 ft per sec

oobleck · Answer

(A) -16t^2+30t+1000 = 0 h=0 when t = 8.90 (B) for the sound, time = distance/speed. So, what do you think?