a girl with a mass of 47 kg sits on one end of a seesaw that 3.0 m long and is pivoted 1.3m from the girl. if the seesaw is just balanced when a boy sits at the opposite end, what is his weight?
-
47 * 1.3 = X * 1.7 ==> X = ??
Because the see-saw is not rotating, the sum of the moments must be zero.
One moment is clockwise, the other counter-clockwise so they are equal.
Remember the question asks for his weight, not his mass.
Because the see-saw is not rotating, the sum of the moments must be zero.
One moment is clockwise, the other counter-clockwise so they are equal.
Remember the question asks for his weight, not his mass.
-
Perform a moment balance to get 35.9 kg ~ 36 kg
To get the weight in newtons you multiply by 9.81 m/s2 and get about 352 N
mr. 30 year exp engineer pointed out how i overlooked the difference between mass (in kg) and weight (in N) :p
To get the weight in newtons you multiply by 9.81 m/s2 and get about 352 N
mr. 30 year exp engineer pointed out how i overlooked the difference between mass (in kg) and weight (in N) :p