Answer:
Among the options you've provided, the object that is an example of a mechanical wave is:
- Police siren
Mechanical waves are waves that require a medium (substance) to travel through, and they transfer energy by causing particles of the medium to vibrate. In the case of a police siren, the sound waves produced by the siren travel through the air, which acts as the medium, causing the air particles to vibrate and carry the sound energy from the siren to your ears.
The other options you've listed (light from a flashlight, microwaves used to heat food, sunlight) are not mechanical waves. They are all forms of electromagnetic waves, which do not require a medium to travel through and can propagate through a vacuum.