Answer:
33.3 g ≈ 33 g
Explanation:
Please see attached photo for explanation.
From the attached photo, M is the mass that we must obtain to balance the plank.
The mass, M can be obtained as follow:
Anticlockwise moment = clockwise moment
Anticlockwise moment = 50 x 20
Clockwise moment = M x 30
Anticlockwise moment = clockwise moment
50 x 20 = M x 30
Divide both side by 30
M = (50 x 20)/30
M = 33.3 g ≈ 33 g
Therefore, the mass that will balanced the plank at the 70 cm length is appropriately 33 g
