Xiao Yong rode his bicycle on a straight expressway for 600m at a constant speed, and it took him 2 minutes to find 1.

1.v = s/t = 600m/120s = 5m/s.

2. Because it is vertical.

F = G = 680N Newton

S = 0.04m m2 * 2 = 0.08m m2.

P=F/s=680N/0.08=8500pa