Naruto P asked:
according to the 1998 Guinness Book of World Records stuntman Dan Koko fell a distance of 360 feet into an airbag after jumping from the Vegas World Hotel and Casino. The distance d in feet traveled by a freefalling object in t seconds is given by the formula d = 16t 2. To the nearest tenth of a second, how long did the stuntman’s freefall last?
answer.
A)4.7 seconds
B)6.9 seconds
C)6.2 seconds
D)5.8 seconds
E)none of these
From the problem we know that:
360=16t^2 divide both sides by 16
22.5 = t^2 take square root of both sides
4.7434 = t round to nearest tenth
4.7 = t
Comment by Jeanne C — January 13, 2010 @ 8:34 am
If distance = 16 t² then
360 = 16 t²
t² = 22.5
t = 4.743 secs (answer a)
Comment by Joe L — January 14, 2010 @ 9:39 pm
Your formula is incorrect.
To determine the time that an object takes to fall a given distance, you must rearrange the equation x = gt²/2. You must also note ‘assuming negligible wind resistance’ to the falling body.
where:
x is the distance the object falls
g is the acceleration due to gravity
t is time
resolve this to:
t = √(2x/g)
Comment by HairyBoater — January 16, 2010 @ 2:40 pm