Let’s denote the position where the 47-g mass should be placed as x (in cm from the 0 cm mark). The balance point is at the 50 cm mark, so the distance from the balance point to the 47-g mass is |50 - x|.
Setting the sum of moments on each side of the balance point equal gives us:
(50 - 29) cm * 42 g = |50 - x| cm * 47 g
Solving this equation will give us the value of x. Note that there will be two solutions, one for x < 50 and one for x > 50, but since we already have a mass at the 29 cm mark, we are interested in the solution where x > 50.
Let’s solve this equation:
Simplify the left side: 21 cm * 42 g = 882 g*cm
Divide both sides by 47 g: 882 g*cm / 47 g = 18.77 cm
Add 50 cm to get x: 50 cm + 18.77 cm = 68.77 cm
So, you would place the 47-g mass at the 68.8 cm mark (rounded to one decimal place) on the meter stick to balance the system.