Question

Anna and Jon sit on a seesaw. Anna has a mass of 60 kg and sits 2 m from the center. Jon has a mass of 70 kg. How far from the center should Jon sit so the seesaw is balanced? Select the correct answer O 150 mayores Your Answer O 490 m O Cannot be determined m O 1.7 m O 2.3 m

Answer 1

Answer:

dJ = 1.7 m

Explanation:

The Equation of the Balancing the moments in the center of the seesaw  is like this:

∑Mo = 0

Mo = F*d

Where:

∑Mo : Algebraic sum of moments in the center(o) of the balance

Mo : moment in the o point ( N*m)

F  : Force ( N)

d  : distancia of the force to the the o point  ( N*m)

Data

mA = 60 kg : mass of the Anna

mJ = 70 kg :  mass of theJon

dA = 2 m : Distance from Anna to the center of the seesaw

g: acceleration due to gravity

Calculation of the distance from Jon to the center of the seesaw  (dJ)

∑Mo = 0   WA : Ana's weight   , WJ : Jon's weight

W = m*g

(WA)(dA) - (WJ) (dJ) = 0

(mA*g)(dA) - (mJ*g)(dJ) = 0

We divide by g the equation:

(mA)(dA) - (mJ)(dJ)= 0

(mA)(dA) = (mJ)(dJ)

$d_{J} = \frac{m_{A} *d_{A}}{m_{J}}$

$d_{J} = \frac{60 kg *2 m}{70 kg}$

dJ = 1.7 m