Average speed= total distance/total time =12km/h
Rutherford's nuclear model stated that a cloud of negative electrons surround the nucleus however scientists realized that electrons in a cloud around the nucleus of an atom would be attracted to the nucleus, causing the atom to collapse. Thus Bohr's model proposed that electrons were contained in shells and they orbit the nucleus at fixed distances.
Answer:
1e , 2j , 3c , 4d , 5k , 6a , 7i , 8b , 9m , 10h ,11g , 12f , 13l .
B. Inelastic collision.
In elastic collision , both momentum and kinetic energy are conserved while in inelastic collision only momentum is conserved. there is some loss of energy in inelastic collision during collision.
During the collision of bat with baseball, some energy gets lost to heat and sound. hence the kinetic energy is not conserved although the momentum is conserved.