Help!!! If anyone could do one of these, i'm confused on how I should write the equation down.

F=ma=m(change in velocity/change in time)
Number 1
F=ma
F=55kg(1.1ms^-1/1.6s)=37.8N
Number 2
F=ma
F=0.440kg(10ms^-1/0.02s)=220N
Number 3
F=ma
F=1400kg(15ms^-1/0.73s)=2.88*10^3N or 28,767N
Any questions please feel free to ask.