9.when you rub your hands together on a cold day, you use friction to transform
a. mechanical energy into thermal energy.
b. thermal energy into nuclear energy.
c. nuclear energy into electrical energy.
d. electrical energy into electromagnetic energy.

I believe the correct answer from the choices listed above is option A. When you rub your hands together on a cold day, you use friction to transform mechanical energy into thermal energy. As you rub, heat is being produced which warms you during a cold day.