6) If a mass of an object is decreased to half and acting force is reduced by quarter the acceleration of its motion,
a) Increases to its double
b)remains constant
d) Increases to its four times
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Magma  is composed of molten rock and is  stored  in the earth's crust. lava is  magma  that reaches the surface of our planet through a volcano vent.

You need to be more specific.  i really don't know what a "motion map" is.you can draw a graph of an object's position, distance, displacement, speed,velocity, or acceleration versus time, or you can draw a graph of the object's x-position versus its y-position and not give any information about time at all.if the graph presents position or displacement against time,  then constant velocity is a straight line . . i.e. a line that has  constant slope.if the graph shows speed against time, then constant velocityis a horizontal piece of line.if the graph shows acceleration against time, then constant  velocity is a piece of line that lies on the x-axis . . it's value is zero. 

Iwould think it would be efficiency.

Question 1 answer: make sure you eat healthy foods and excercise atleast once a day.question 2 answer: sometimes bullying . bullying lowers a persons self-esteem sometimes which can make them not care for themselves to much making them feel bad about there body structer. that or they just have a bad body structer and there family/doctor said its unhealthy how they eat.