What is the scientific definition of speed?

In  physic speed  is  defined  to  as  scalar  quantity  which  is  defined  to  as  the  rate  at  which  an  object  covers  object.  The  speed  of  an  object  is  the  magnitude of  its  velocity.  spend  has  no  direction  and  is  measured   how  a  object  move relative  to   a  reference  point.

This is what i found on google “phytoplankton, tiny organisms that live in the ocean, are autotrophs. some types of bacteria are autotrophs. most autotrophs use a process called photosynthesis to make their food.” i hope this you for what your looking for