The time t in seconds it takes an object to fall d feet is given by the following equation.
(a) A tower is 1,490 feet tall. How long would it take a penny to fall to the ground from the top of the bell tower? (Round your answer to two decimal places.)
t= ? seconds
(b) An object took 25 seconds to fall to the ground. From what distance must it have been dropped?
d=? feet
(a) A tower is 1,490 feet tall. How long would it take a penny to fall to the ground from the top of the bell tower? (Round your answer to two decimal places.)
t= ? seconds
(b) An object took 25 seconds to fall to the ground. From what distance must it have been dropped?
d=? feet
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In this case the usual equation is
s(t) = s0 + v0t + .5a(t)^2
For the first problem s0 = 1490, v0 is 0 (assuming it was simply dropped) and a is the acceleration
dues to gravity which is usually given as -32 ft/sec^2
So you have
s(t) = 1490 - 16t^2 and you need to know how long it takes to get to s(t) = 0
1490 - 16t^2 = 0
t^2 = 1490/16 = 93.125
t = sqrt(93.125) = 9.65
for the 2nd one you know t, and you need to find S0
s0 - 16(25)^2 = 0
s0- 10000 = 0
so s0 = 10000
s(t) = s0 + v0t + .5a(t)^2
For the first problem s0 = 1490, v0 is 0 (assuming it was simply dropped) and a is the acceleration
dues to gravity which is usually given as -32 ft/sec^2
So you have
s(t) = 1490 - 16t^2 and you need to know how long it takes to get to s(t) = 0
1490 - 16t^2 = 0
t^2 = 1490/16 = 93.125
t = sqrt(93.125) = 9.65
for the 2nd one you know t, and you need to find S0
s0 - 16(25)^2 = 0
s0- 10000 = 0
so s0 = 10000
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where is the "following equation"? just substitute the "d" with 1490 feet in (a), and substitute "t" with 25 seconds in part (b).