Explanation:
momentum = mass x velocity
initial momentum = 100 x 15 = 1500kgm/s
after momentum = 100 x 20 = 2000kgm/s
a =(v-u)/t
a = (20-15)/10
a = 5/10
a = 0.5m/s²
f = ma
f = 100 x 0.5
f = 50N
A=atomic mass
Z=atomic number (nº of protons).
N=neutons.
A=Z+N
Data:
A=39
Z=19
A=Z+N
39=19+N
N=39-19=20.
It therefore has 20 neutrons in its nucleus.
