Average Velocity and Acceleration Calculations for Walking Man

[InsTanCeZ]

Homework Statement

From t = 0 to t = 5.00 min, a man stands still, and from t = 5.00 min to t = 10.0 min, he walks briskly in a straight line at a constant speed of 1.9 m/s.

Homework Equations

(a) What is his average velocity vavg in the interval 2.000 min to 7.60 min? ___m/s

(b) What is his average acceleration aavg in the interval 2.00 min to 7.60 min? ___m/s2

(c) What is vavg in time 3.00 min to 9.00 min? ___m/s

(d) What is aavg in time 3.00 min to 9.00 min? ___m/s2

The Attempt at a Solution

a) 1.9*2.6/5.6 = .882 m/s right

b) 1.9/5.6/60 = .006 m/s2 wrong

c) 1.9*2.6/7 = .707 m/s wrong

d) 1.9/6/60 = .005 m/s2 wrong

Where did I go wrong?

 

[Simon Bridge]

how do you determine average velocity and average acceleration?
why are you dividing by 60 in b and d?
where did you get the 2.6/7 in c?
compare - how did you get the 2.6 and the 5.6 in a?