<span>The Balmer series or Balmer lines in atomic physics, is the designation of one of a set of six named series describing the spectral line emissions of the hydrogen atom. The Balmer series is calculated using the Balmer formula, an empirical equation discovered by Johann Balmer in 1885. this is all I know sorry</span>
Subduction zone is not a plate boundary.
Answer:1) 100 gm mass should be placed at 95 cm mark.
2) Mass of 112.5 gm should be placed at 90 cm mark.
Explanation:
For equilibrium of the meter stick the sum of the moment's generated by the masses should be equal and opposite
Answer to part b)
Since a meter stick is 100 cm long and it is pivoted at it's center i.e at 50 cm
Thus
1) Moment generated by 100 gm mass about center = 
Let a mass 'm' be placed at 90 cm mark thus moment it generates equals
Equating both the moments we get
Answer to part a)
Let the 100 grams weight be placed at a distance 'x' right of center
Moment generated by 100 grams weight equals
equating the moments of the forces we get
thus the mass of 100 gm should be placed at 95 cm mark in the scale.
The message is the information being communicated from one place to another.
It used to be called the "intelligence". But as time went on, it became
harder to ignore the obvious fact that that was going too far, and the
label was changed to the more IQ-neutral "message".
The acceleration of the rock is the gravitational acceleration due to earth which is around 9.8 m/s^2. As the rock travels upwards it is working against the constant force of gravity and when it reaches the top it is the force of gravity that will cause a cause in the direction of the rocks velocity and cause it to accelerate towards earth. Using the equation a = F/m, the acceleration due to gravity exerts a force per unit mass on an object causing the object to accelerate, anything above earth surface will therefore have an external gravitational force action on it (in terms of projectile motion). So at the top of the rocks trajectory, the acceleration of the rock will be g (9.8) as a constant force is gravity is exerted on the rock throughout its path.
