Alex tries on Rehaneh's platform shoes in the concourse on level 2. To test her ability to walk in the shoes she moves at an average speed of 0.5 m/s for 5 s followed by 1.0 m/s for 8.0 s. Calculate Alex's average speed for entire test walk.
2007-02-10 11:56:39 · 2 answers · asked by avant1991 3 in Science & Mathematics ➔ Physics
This is a common problem. You have to know that the average speed equals v = s / t, where s is the distance of the entire walk and t is the time it took her to make the walk.
t = t1 + t2 = 5 s + 8.0 s = 13 s
s = s1 + s2 = v1 x t1 + v2 x t2 = 0.5 m/s x 5 s + 1.0 m/s x 8.0 s =
= 2.5 m + 8 m = 10.5 m and
v = 10.5 m / 13 s = 0.77 m/s
2007-02-10 12:03:54 · answer #1 · answered by Dorian36 4 · 1⤊ 2⤋
average speed = total distance traveled / time taken
= (0.5*5+1*8)/(5+8)
= 10.5/13
= 0.808 m/s
2007-02-10 20:40:54 · answer #2 · answered by san 3 · 0⤊ 1⤋