Determine the acceleration (in m/s2) of an object which . 1. moves in a straight line with a constant speed of 20.0 m/s for 12.0 seconds 2. changes its velocity from 12.1 m/s to 23.5 m/s in 7.81 seconds 3. changes its velocity from 0.0 mi/hr to 60.0 mi/hr in 4.20 seconds 4. accelerates from 33.4 m/s to 18.9 m/s over a distance of 109 m

1) 0 m/s²

2) 1.5 m/s²

3) 6.38 m/s²

4) -3.47 m/s²

Explanation:

The acceleration is given by:

1)

For the first question, the acceleration is zero, because there is no change on its velocity:

2)

3) here we have to make an conversion:

4) here we have to use the following formula:

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.

the minimum amperage that the current in this wire would have to have so that its weight is completely supported by the magnetic force due to earth's field, assuming that no other forces except gravity act on it