A change in position in relation to a reference point is: a. acceleration
b. displacement
C. speed
d. velocity
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it would be b. displacement

An object is in motion if it changes position relative to a reference point. You assume that the reference point is stationary, or not moving. Frame of Reference Speed If you know the distance an object travels in a certain amount of time, you can calculate the speed of the object. Speed! Hope this helped

You’re able to swallow food despite your orientation; this is due to your esophagus doing its job. As food enters your esophagus, the muscles start contracting, preventing the bolus from moving backward.