what is the velocity when the wrench strikes the ground?
could you tell me which formula to use (acceleration, velocity, or displacement?)
I dont understand what the variables are or which formula to use. please explain!! Thanx
2007-09-20 12:03:50 · 5 answers · asked by Smiley 3 in Science & Mathematics ➔ Physics
Use v^2 = u^2 + 2as, where:
v is the final speed,
u is the initial speed, zero in this case since it falls from rest,
a is the acceleration due to gravity, and
s is the distance through which the wrench has fallen. So:
v^2 = u^2 + 2as
v^2 = (0)^2 + 2 x 9.81 x 80.
I`m sure that you can calculate the rest !
Hope this helps, Twiggy.
2007-09-20 12:25:10 · answer #1 · answered by Twiggy 7 · 0⤊ 0⤋
Since the question asks what is the velocity, shouldn't you be using the equation for velocity? You have to solve for the time it took for the wrench to fall first, then solve for the final velocity using the acceleration constant of gravity. I got 39.6m/s.
2007-09-20 12:21:43 · answer #2 · answered by ShortnSweet 4 · 1⤊ 1⤋
39.6 meters per second is the speed the wrench hits the ground. First you have to find the time involved. Divide 80 meters by 4.9, this is half of g, find the square root of this number, this will be the time of the free fall, multiply this by 9.8 and you get the correct answer.
2007-09-20 12:36:08 · answer #3 · answered by johnandeileen2000 7 · 0⤊ 1⤋
There is not enough info to solve, you neen to know the weight of the wrench
2007-09-20 12:36:23 · answer #4 · answered by expy916 2 · 0⤊ 2⤋
v = √(2ax) = √(2*9.8*80) = √1568 = 39.6 m/2
Doug
2007-09-20 12:24:13 · answer #5 · answered by doug_donaghue 7 · 1⤊ 1⤋