Answer:
-4000 N
Step-by-step explanation:
newton second law F=ma
m=1000kg
vi=20m/s
vf=0
d=50 m
vf^2=vi^2+2ad
0=20^2+2a×50
100 a= -400
a= -4 m/S2
F=ma = 1000×-4 = -4000 N
3.5m questions
4.4m answers