(i) v = u + at1 40 = 0 + a × 20 a = 2 m/s2 v2–u2 = 2as 402 – 0 = 2 × 2 s1 s1 = 400 m (ii) s2 = v × t2 = 40 × 20 = 800 m (iii) v = u + at 0 = 40 + a × 40 a = –1 m/s2 02–402 = 2(–1)s3 s3 = 800 m Total distance travelled = s1+s2+s3 = 400 + 800 + 800 = 2000 m Total time taken = 20 + 20 + 40 = 80 s Average velocity =