Calculate the instantaneous speed and distance fallen for an object that falls freely from rest for 8 seconds.

Calculate the instantaneous speed and distance fallen for an object that falls freely from rest for 8 seconds.
Explanation would be nice, and I should get rid of that part saying how I wanted the answer71 mths ago

you just need to know that acceleration due to gravity is approx. 9.81 meters per second squared.
The distance can be calculated with the formula
s = u*t +1/2 a* t^2
s=distance, u=initial speed, t=time and a=acceleration
since u=0 in this case we simply have
s= 1/2 a* t^2..... here is my answer.
s=1/2 *9.81*(6^2) = 176.58m
final speed is given by
v=a*t = 9.81*6 = 58.86 meters per second
average speed is given by
av=distance/time = 176.58/6 = 29.43 meters per second

Source: calculated

71 mths ago

Answers - 4

Holy smoke!!! The bright folks will have to answer this one. I won't even get out of the starting gate.

71 mths ago

1. What is its instantaneous speed?
vo = 0 m/s, a = 10 m/s2, t = 8 s, v = ?
v = at = (10 m/s2)(8 s) = 80 m/s
2. How far has it fallen?
* a = 10 m/s2, t = 8 s, d = ?
distance equation = 0.5(10 m/s2)(8 s)2 = 320 m
* Or, d = vy/2 = 0.5(80 m/s)(8 s) = 320 m

71 mths ago

The previous method is correct, but the version of the question I see sets t = 8, not 6... so u = 0, t = 8, a = g = 9.81m/s^2, v = a*t = 78.48m/s and s = u*t + 0.5*a*t^2 = 313.92m