A1st phase:
v= at, t=v/a=\(\frac{20 m/s}{2m/s^{2} }\)=10s
2nd phase:
0 m/s= 20 m/s - at, at= 20 m/s, t=\(\frac{20 m/s}{1m/s^{2} }\)=20s
Total time: t1+t2=10 s+20 s = 30 s
b)Formula: s=v0t+at²/2 or s=v0t-at²/2
1st phase:
s=0+\(\frac{2*10^{2} }{2}\)=100m
2nd phase:
s=20 m/s20 s-\(\frac{1*20^{2} }{2}\)=200 m
Total distance traveled: s1+s2 = 100 m + 200 m = 300 m.
