how long did it take?
40t + 1/2 at^2 = 100
40 + at = 30
Solve that to find a and t.
Now find another t such that 30 + at = 0
Note that a is in km/s^2
The velocity of a train is reduced uniformly from 40km/sec to 30km/sec travelling a distance of 100km.
A. Calculate the retardation
B. How much farther will it travel before coming to rest, assuming the same retardation.
2 answers
A. V^2 = Vo^2 + 2a*d.
30^2 = 40^2 + 2a*100.
900 - 1600 = 200a,
a = -3.5km/s^2.
B. V^2 = Vo^2 + 2a*d.
0 = 40^2 + (-7)*d,
d = __km.
d - 100km = __km farther.
30^2 = 40^2 + 2a*100.
900 - 1600 = 200a,
a = -3.5km/s^2.
B. V^2 = Vo^2 + 2a*d.
0 = 40^2 + (-7)*d,
d = __km.
d - 100km = __km farther.
3 answers