Answer: 3.0 m
Explanation:
Moment of force about the fulcrum is equal to balance the see saw:
mg d = m'g d'
It is given that
mass of the girl, m = 30 kg
distance from the fulcrum, d = 4.0 m
mass of the boy, m' = 40 kg
Distance from the fulcrum, d' = ?
⇒30 kg×4.0 m = 40 kg× d'
⇒d' = 120 kg.m / 40 kg = 3.0 m
Thus, in order to balance the see saw, a 40 kg boy must sit at a distance of 3.0 m from the see saw.
Answer:
The answer is 3m
Explanation:
This question has to do with balancing of moment
The moment of force about the fulcrum
Given the mass of the girl =30kg
To force Fg=30*10=300N
Distance of girl from fulcrum l= 4m
Mass of boy 40kg
TO force Fb=40*10=400N
Distance of the boy from fulcrum =?
We know that moment of force about a point M=force*distance
I.e M=f*l
For the boy to cause a balance
His moment must be equal to that of the girls
Therefore
Fg*l=Fb*l
300*4=400*l
1200=400l
L=1200/400
L=3m
Hence the boy must seat 3m away from the fulcrum to balance the seesaw
What is a moment?
A moment is a turning force about a point, The moment is equal to the magnitude of the force multiplied by the perpendicular distance between its line of action and the axis of rotation
