In the Ames Test, the appearance of his revertants in the presence of a non-mutagenic control compound indicates that .

Answer & Explanation:  The Ames test examines the mutagenic effects of chemicals ; as such, it detects whether a given chemical can cause a reversion mutation in his- bacteria. While this is the purpose of the test, some of the reversion mutations are not caused by the mutagen being tested  for. The appearance of his revertants in the presence of a non-mutagenic control compound therefore indicates that His+ revertants on the control plate are the result of spontaneous mutation.

the answer would be a

(newtons first law)

conservation of momentum law states :

momentum before collision = momentum after collision

momentum p (kg-m/s)= mass * velocity

say moving car=1 000 kg, velocity = 10 m/s then p = 1 000*10= 10 000 kg-m/s

say still car = 2 000 kg, velocity = 0 m/s then p = 2 000* 0 = 0 kg-m/s

total momentum prior to collision = 10 000 + 0 = 10 000 kg-m/s

momentum after collision = 10 000 kg-m/s

mass now = 1 000 kg+2 000 kg = 3 000 kg

10 000 = 3 000 kg* velocity m/s

10 000/3 000 = velocity

3.33 m/s = velocity after collision

an impulse is a force applied over time , momentum is exclusive of external forces and a perfect collision is implied