Friction can change work into heat. True or False

Awave is produced in a rope. the wave has a speed of 33 m/s and a frequency of 22 hz.

Apulley with mass mp and a radius rp is attached to the ceiling, in a gravity field of 9.81 m/s2 and rotates with no friction about its pivot.

Acamcorder has a power rating of 20 watts. if the output voltage from its battery is 9 volts, what current does it use?