let the length of the beam be "L"
from the diagram
AD = length of beam = L
AC = CD = AD/2 = L/2
BC = AC - AB = (L/2) - 1.10
BD = AD - AB = L - 1.10
m = mass of beam = 20 kg
m₁ = mass of child on left end = 30 kg
m₂ = mass of child on right end = 40 kg
using equilibrium of torque about B
(m₁ g) (AB) = (mg) (BC) + (m₂ g) (BD)
30 (1.10) = (20) ((L/2) - 1.10) + (40) (L - 1.10)
L = 1.98 m
Answer: 
Explanation:
The acceleration of an object can be calculated by using Newton's second law:

where
F is the net force applied on the object
m is the mass of the object
a is its acceleration
In this problem, we have F=125 N and m=25.0 kg, so we can rearrange the equation to calculate the acceleration:

<h2>Answer: It becomes an Ion
</h2>
When an atom has gained or lost electrons (negative charge), it becomes an ion.
In this sense:
<h2>I
ons are atoms that have <u>
gained or lost</u>
electrons in their electronic cortex.
</h2><h2>
</h2>
If a neutral atom <u>loses electrons</u>, it remains with an excess of positive charge and transforms into a positive ion or <u>cation</u>, whereas if a neutral atom <u>gains electrons</u>, it acquires an excess of negative charge and transforms into a negative ion or <u>anion</u>.
It is then how ions form bonds with other atoms differently depending on the number of electrons they have.
Answer:
K = ρL²g
Explanation:
Consider L as the length of the raft inside the water when the raft is displaced through additional distance y;
Then:
F = upthrust ( restoring force) = weight of the liquid displaced.

where;
A = L²

F = ky.
Then,


Divide both sides by y
K = ρL²g