Answer:
3240 Km/hr
Step-by-step explanation:
moving piece of paint m = 5.0 g and velocity 8.1*10^3 m/s
We know that
1km=1000m
and 1hr = 3600 s
By momentum conservation we have
m1v1 = m2v2
so v2 = m1/(m2×v2)
=5×10^3/45×8.1 =900
so 900 m/s = 900 x3600/1000 = 3240 Km/hr