In frozen Minnesota the Winter Sports Carnival includes some unusual events. Sin
ID: 2236927 • Letter: I
Question
In frozen Minnesota the Winter Sports Carnival includes some unusual events. Since it is dangerous to run on ice, each runner runs on ice, each runner runs on a heavy (240 kg) and long (40 m) wooden plank, which itself rests on the smooth and horizontal ice. One of the competitors is a 60-kg woman who runs the length of the plank in 4.4 seconds, quite an impressive time. Her performance is viewed by a crowd huddled on the ice. The performance that they see is less impressive. With what speed does the crowd see the woman moving?Explanation / Answer
v1 + v2 = 40/4.4 = 9.0909 m/s
m1 v1 = m2 v2 ==> v2 = m1/m2 v1 = 60/240 * v1 = 0.25 v1
v1 + 0.25 v1 = 9.0909
v1 = 9.0909/1.25 = 7.27 m/s