The first one would be thermal energy
Answer:

Explanation:
Let say the empty wagon has mass "M"
now by newton's II Law we will have

now it is given that empty wagon is pulled with acceleration 1.4 m/s/s
now we will have

now a child of mass three times the mass of wagon is sitting on the empty wagon
so here we have


so we have

Answer:
D. all sounds are caused by vibrations
Explanation:
Radio waves, Middle-C, and halitosis are not forms of light.