Question

Some students observing a classroom device being used noticed the below energy transformations.

energy to mechanical to sound


Which device were the students most likely observing?


A triple beam balance measuring an object’s mass


A pencil sharpener plugged into a wall outlet


A projector displaying a diagram on the screen


A working flashlight used to light up a dark corner

Answer 1

A pencil sharpener plugged into a wall outlet is the device that converts electrical energy to mechanical energy, which in turn generates sound while sharpening pencils.

Step-by-step explanation:

The device that the students were most likely observing that converts electrical energy to mechanical energy to sound is a pencil sharpener that is plugged into a wall outlet. In this device, electrical energy is transformed into mechanical energy as the motor turns the blades of the sharpener. As pencils are sharpened, friction between the pencil and the sharpener creates sound.