1.A man carries a 3 m long plank which has a mass of 3 kg over his shoulder. The tip of the plank extends 1 m in front of his shoulder. Given that his hand rests 0.3 m in front of his shoulder on the plank and that the weight of the plank is evenly distributed,
a) how much force does he need to exert in order for the plank to remain in the horizontal position over his shoulder?
b) what is the force exerted by his shoulder on the plank in this position?