I DONT GET 5c, 5f, 7c, 7d, 7a, Please ANSWER ASAP :) Thank YOU 6. A piano droppe
ID: 2910214 • Letter: I
Question
I DONT GET 5c, 5f, 7c, 7d, 7a,
Please ANSWER ASAP :)
Thank YOU 6. A piano dropped from a cliff takes 4 seconds to hit the ground. How long will it take for a piano dropped from cliff twice as hight to hit the ground? Before answering this question, say whether your answer will be less than, greater than, or equal to 8 seconds 7. At the same time that a watermelon is dropped from the top of a 100 foot tall building, a banana is thrown up from the g the height of the banana above the ground after s seconds is given by h0-162+ a. Fi with an initial velocity of 24 fusec (so 24t) nd the height of the watermelon above the ground when the banana is at its highest point. b. When is the watermelon 76 feet above the banana? c. Which fruit hits the ground first? d. When is the first time that the two fruits are the same height above the ground? 2 8. A rock is dropped into a well 550 feet deep. a. How long will it take the rock to hit the water? b. Sound travels at the speed of 1100 f/sec. After the rock hits the water, how long wi t take the sound of the splash to reach your ears? .How long after dropping the rock will you hear the splash? ) How long will it take for an object dropped from 64 feet above the ground to re e ground? How long will it take for an object dropped from 144 feet above the ground to ground? How long will it take for an object dropped from H feet above the ground to ground? Express the height H from which an object is dropped as a function of the ti e to reach the ground.
Explanation / Answer
7 a)we know initial velocity(u) of banana is 24 ft/s
At highest point final velocity (v) will ne zero
=> we know v =u + at
Here a is equal to g whicg is 32. As the banana is going upwards ,a will be negative i.e. - 32
=> 0= 24 -32t
=> t= 24/32=0.75seconds
Now height of watermelon from ground = height from which it was thrown - distance travelled by watermellon in 0.75 seconds
=> h= 100 - ( ut + 1/2gt2)
We know u =0 for watermellon as it is a freefall ,g =32 and t =0.75
=>h =100 -(1*32*(0.75)2/2)
=> h =100 -( 18/2)
=> h= 100- 9= 91
=> h = 91 ft above the ground
7c) For watermelon, time taken to hit the ground be t seconds
=> h = 0*t + 1*32*t2/2=100
=> 100= 16t2
=> t = sqrt(100/16)
=> t = 10/4 = 2.5 seconds
Where as we have already calculated for a part that time required to reach banana at top is 0.75 seconds
Total time to reach back to ground is double of that which is 2*0.75 = 1.5 seconds
Hence banana will git grpund first
7d) 100 -distance travelled by watermelon =height gained by banana
= 100 - ( 0 + 1*32*t2/2)= 24t - 1*32*t2/2
=> 100= 24t
=> t= 4.17 seconds
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