Which statements about acceleration are true? check all that apply. a. the si units of acceleration are m/s2. b. for acceleration, you must have a number, a unit, and a direction. c. to calculate acceleration, divide the change in speed by the change in time. d. the symbol for acceleration is .

The first thing you should know is that acceleration is a vector, therefore, it has magnitude, and direction.

By definition, we have that the vector acceleration is given by:

Where,

dv/dt: derived from the velocity vector with respect to time,

Therefore, the units of the vector acceleration are:

The symbol of acceleration is:

The statements about acceleration that are true are:

a. the si units of acceleration are m/s2.

b. for acceleration, you must have a number, a unit, and a direction.

d. the symbol for acceleration is (True, only if the symbol is the same as above)

A is True:

The formula for acceleration is:




Because the unit of velocity is m/s and the unit of time is second this is what happened:

 ÷

 ÷X =  

B is True:

Acceleration is a vector quantity, so that means it should have both magnitude and direction. When given an acceleration, the sign usually indicates the direction. A negative value is a sign that it is decelerating and not accelerating. 

D could be true only if:

Your question is actually broken so we do not know the symbol you are showing. But in general, the symbol of acceleration is a letter "a" with an arrow on top. You can see in the picture attached to see the symbol I am referring to. 

C is not true because acceleration is the change in VELOCITY over time. Velocity and speed are different. 

A. they hold atoms  together with a molecule.its a force that exist between molecules. hope this .