Question

A father (75 kg) was standing watching TV, minding his own business when one of his kids (20 kg) approached him at 2m/s heading at 0 degrees and jumped onto his back. Another kid (15 kg) approached him at 3m/s heading at 45 degrees to the first kid and also jumped on him at exactly the same time. Immediately after impact, in what direction did the group go (measured in degrees with respect to the first kid)

Answer 1

Answer:

Explanation:

Conservation of momentum

Let's say the first child was headed north

North momentum

75(0) + 20(2) + 15(3sin45) = (75 + 20 + 15)vn

vn = 0.6529 m/s

East momentum

75(0) + 20(0) + 15(3cos45) = (75 + 20 + 15)ve

ve = 0.28927 m/s

θ = arctan(0.28927/0.6529)

θ = 23.896...

θ = 24° east of north