What is meant by an objects acceleration?

a. distance covered in an amount of time
b. how fast an object is changing speed
c. force needed to change an objects motion
d. magnitude of a push or pull

Will you chech and finish these for me, because i am stumped with them.

Kate is working on a project in her tech education class. she plans to assemble a fan motor. which form of energy does the motor convert most of its electric energy into? a. light energy b. motion energy c. sound energy d. thermal energy

Hydrogen and helium are both members of?