# physics

posted by .

A 5 m long see saw has a child whose mass is 25 kg sitting on one end. How far in meters from the center should a 70 kg adult sit on the opposite side for the see saw to balance?

• physics -

Let A = the child and B = adult person.
To balance this beam, the moment of the right hand side (B) must equal the moment of the left hand side (A).

M(A) = M(B)
m(A)*g*2.5 = m(B)*g*d(B)
62.5 = 70*d(B)

=> d(B) = 70/62.5 = 1.12m

I hope this will help

## Similar Questions

1. ### math

1. Two children balance a see-saw in horizontal equilibrium. One weighs 80 lb. and the other weighs 60 lb. and is sitting 4ft. from the fulcrum. Find the force the fulcrum applies to the beam and the distance to the fulcrum to the …
2. ### math

1. Two children balance a see-saw in horizontal equilibrium. One weighs 80 lb. and the other weighs 60 lb. and is sitting 4ft. from the fulcrum. Find the force the fulcrum applies to the beam and the distance to the fulcrum to the …
3. ### math

1. Two children balance a see-saw in horizontal equilibrium. One weighs 80 lb. and the other weighs 60 lb. and is sitting 4ft. from the fulcrum. Find the force the fulcrum applies to the beam and the distance to the fulcrum to the …
4. ### physics

1.Can a small child play with a fat child onthe see-saw?
5. ### physics

David and his father sat at the end of a see-saw 2 m from the pivot. where should David's mother sit in order to balance the see-saw
6. ### Physics

Ali and his father sit at the ends of a see-saw, 2 m from the pivot, as shown in figure 5.12. Where should ali's mother sit in order to balance the see-saw?
7. ### Physics

Ali and hid father sit at the ends of a see-saw, 2 m from the pivot, as shown in figure 5.12. Where should ali's mother sit in order to balance the see-saw?
8. ### Physics

39. (Taken from problem 5 at the end of Chapter 9) Look at the children balanced on the see-saw in the figure below. r1 = 1.60 m. The center mass of the seesaw is located 0.16 m to the left of the pivot point. The seesaw board has …
9. ### Physics

A 45 kg girl is sitting on one end of a see-saw, 0.6 m away from the the pivot pt. How far away form the pivot pt must a 60 kg boy sit on the other side in order for the see saw o be balanced?
10. ### Physics College

A see-saw 3.76 meters long perfectly balances on its own at its center. Two children get on the see-saw. One, weighing 345 N, sits at the left hand end. The other, sits 25.0 cm in from the right hand end. The see-saw is perfectly balanced …

More Similar Questions