a book falls off the top of an 8-foot shelf. Theodore is 4-feet tall. if is takes theodore 2 seconds to respond to the fall and get out of the way, does the book hit him?
+130511 a book falls off the top of an 8-foot shelf. Theodore is 4-feet tall. if is takes theodore 2 seconds to respond to the fall and get out of the way, does the book hit him?
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Let's see how much Physics I can remember.
The position "y" of any object at time t is given by:
y = -16t2 + vot + h
Where vo is the original velocity ( 0, in our case) and h is the original height (8 ft.). Note that y = 4 feet above the ground. So we have...
4 = -16t2 + 8 which simplifies to
0 = -16t2 + 8 and solving for t, we get
t = ± (1/2) second
Rejecting the negative, we get that the book falls 4 ft. in (1/2) second !!
Move faster, Theodore !! 
+130511 a book falls off the top of an 8-foot shelf. Theodore is 4-feet tall. if is takes theodore 2 seconds to respond to the fall and get out of the way, does the book hit him?
----------------------------------------------------------------------------------------------------------------------------
Let's see how much Physics I can remember.
The position "y" of any object at time t is given by:
y = -16t2 + vot + h
Where vo is the original velocity ( 0, in our case) and h is the original height (8 ft.). Note that y = 4 feet above the ground. So we have...
4 = -16t2 + 8 which simplifies to
0 = -16t2 + 8 and solving for t, we get
t = ± (1/2) second
Rejecting the negative, we get that the book falls 4 ft. in (1/2) second !!
Move faster, Theodore !!
