Hi, I have this mathematical problem and am getting confused on SOMETHING.. anyway, "Calculate the speed of a rock that is dropped after it has fallen for 7 seconds, ignoring wind resitance."
In meters, it would accelerate at 9.8meters persecond PERSECOND... what is the metric speed?
2006-08-17 15:31:33 · 10 answers · asked by ? 2 in Science & Mathematics ➔ Mathematics
Thaks LoneWolf, Fianally done with homework at 10:40PM, GMT -5:00
2006-08-17 15:40:48 · update #1
v=u+at where u=0, a=9.8 m/s^2 and t=7. The speed would be 68.6 m/s
2006-08-17 15:38:13 · answer #1 · answered by LoneWolf 3 · 1⤊ 0⤋
is this physics? that's what is sounds like. Just use the equation that relates acceleration a to velocity. If you have a textbook, i'm sure you can find that equation. or look online. Velocity equals meters/second, so since that is so, acceleration must equal velocity/time, though you may want to verify that there is no constant multiplied into the equation. it's been 3 years since my last physics class, even though I got A's in both. So just multiply 9.8 meters/ squared seconds by 7 seconds, and go from there. good luck, and let me know if you get the right answer!
2006-08-17 22:40:44 · answer #2 · answered by Bebe 2 · 0⤊ 0⤋
Ignoring wind resistance on the object, the free falling formula on Earth is approximately given by,
d = 0.5 * g * t2
d = distance in meters
g = gravitational acceleration of 9.8 m/s^2
t = number of seconds
d = 0.5 * 9.8 m/s^2 * (7 s)^2
d = 240.1 meters
2006-08-17 22:43:45 · answer #3 · answered by Benny 2 · 0⤊ 0⤋
How much physics backgound do you have? This type of problem is covered in kinematics (physics one). When an object is dropped (regardless of size) it always falls at the same velocity (speed). I am unable to show you the calculations on this computer w/o confusing you. Here is your answer:
68.6(m/s)..
2006-08-17 22:55:19 · answer #4 · answered by Anonymous · 0⤊ 0⤋
Vf= Vo + at
Vf = 0 + 9.8 (7)
final velocity = 68.6 m/s
2006-08-17 22:39:10 · answer #5 · answered by theman 2 · 0⤊ 0⤋
lets stop and think
9.8 meters/sec/sec means it gets 9.8 meters per second faster every second
so 9.8 meters/sec /sec * 7 sec = 68.6 meters/sec
straightforward, right
and you don't even need to look up the equation, but you could
v=at (velocity equals acceleration times time)
2006-08-17 22:38:50 · answer #6 · answered by enginerd 6 · 0⤊ 0⤋
The rocket is dropped from rest, so it starts at zero velocity.
acceleration = (final velocity - intial velocity) / time
OR
a = [vf - vi] / t
vi = 0 (m) / (sec)
a = 9.8 (m) / (sec^2)
t = 7 (sec)
9.8 (m) / (sec^2) = [ vf - 0 (m) / (sec) ] / 7 (sec)
9.8 (m) / (sec^2) = vf / 7 (sec)
vf = 7 (sec) * 9.8 (m) / (sec^2)
= [7*9.8] (m) * (sec/sec^2)
= 68.6 (m) / (sec)
2006-08-18 23:51:16 · answer #7 · answered by Anonymous · 0⤊ 0⤋
speed = distance / time.
speed = 9.8/7
2006-08-17 22:38:13 · answer #8 · answered by wengkuen 4 · 0⤊ 1⤋
9.8*7=68.6
2006-08-17 23:20:42 · answer #9 · answered by Navdeep B 3 · 0⤊ 0⤋
DUH!!!! When you find out let a sistah know.
2006-08-17 22:36:55 · answer #10 · answered by Ms New Booty 3 · 0⤊ 0⤋