Appropriate word inside the parentheses. At constant mass, the
of an object varies (directly, inversely) with the net external force
appiled. That is to say, that an object's acceleration increases as the force applied is (decreased. Increased),
but its acceleration decreases if the force applied is (decreased, Increased)

The net force is directly proportional to acceleration at constant mass while the mass is inversely proportional to acceleration at constant force.

According to Newton's second law of motion, at constant mass, the force applied is directly proportional to acceleration. That is; F = ma

F = force

m = mass

a = acceleration.

As such, when the force applied is increased, the acceleration increases. When the force applied is decreased, the acceleration decreases.

To complete the sentence; At constant mass, the acceleration of an object varies (directly, inversely) with the net external force applied. That is to say, that an object's acceleration increases as the force applied is (decreased, increased), but its acceleration decreases if the force applied is (decreased, increased) At constant force, acceleration varies (directly, inversely) with mass. When subjected to the same amount of net external force, a heavier object will experience (less, greater) acceleration than a lighter one.

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At constant mass, the  acceleration of an object varies (directly) with the net external force  applied. That is to say, that an object's acceleration increases as the force applied is (increased),  but its acceleration decreases if the force applied is (decreased).

Explanation:

Mechanical Force

According to the second Newton's law, the acceleration of an object varies directly proportional to the external net force applied and inversely proportional to the mass of the object.

If the mass is constant, then the acceleration will vary in the same way as the force does.

Completing the sentences:

At constant mass, the  acceleration of an object varies (directly) with the net external force  applied. That is to say, that an object's acceleration increases as the force applied is (increased),  but its acceleration decreases if the force applied is (decreased).

there is no correct list among the choices you've provided.

the list might look something like this:

-- baby human

-- piccolo

-- flute

-- soprano singer

-- trumpet

-- tenor singer

-- trombone

-- baritone singer

-- baritone horn

-- bass singer

-- tuba

since i had to make up the list myself, i made it easy on myself, and i didn't try to shuffle the string instruments and woodwinds into it too.