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:
A ferromagnetic material is a temporary magnet. The domains in a ferromagnetic material are randomly arranged. Under certain actions, the domains align in a particular direction and the material acts as a magnet. The actions that can cause alignment of domains in a ferromagnetic material are:
- rubbing the material against a magnet would cause the alignment of domains in the same direction as of the magnet.
- passing electricity around the material would generate magnetic field which would cause domains to align along the direction of the field.
- placing the material near a strong magnet would cause the alignment of domains in the direction of the field generated by the strong magnet.
Other actions like heating the material, placing the material in a magnetic field of opposite polarity and hitting the material would lead to demagnetization of the magnetic material.
Answer:
Explanation:
Aceleration is a change on the velocity of the object in a given time.
For this case: the initial velocity is
and the final velocity is :
so, the change in velocity is:
and the change in time , according to the problem:
So, the aceleration is:
When wool is rubbed with a balloon, the wool is left with a positive charge as electrons have travelled from the wool to the balloon which means the balloon now has a negative charge.
Now that the balloon has a negative charge, you need to know:
The tissue paper originally contains electrons and protons
The fact that the balloon has a negative charge, it will ATTRACT protons because protons are POSITIVE and electrons are NEGATIVE.
So once they are attracted, they will move closer to one another.
Density is mass divides by volume, so
89.6g / 10cm^3 =8.96g /cm^3
*cm^3 is a standard unit of volume*
