Disposals have a rotating grinder inside. The water should be running and the disposal turned on before washing anything into it. Some times a large amount of food will cause it to jam but more often it is something small like a seed or a pit. In any case if the disposal does not make any sound  then press the reset button on the bottom. It's the red button shown in the photo.

photo of bottom of disposal

They try it again.  If it hums but does not run, immediately turn the switch off.  Take the tool shown below and insert it into the hole shown in the middle of the bottom of the disposal. Crank it to rotate and loosen the inside of the disposal. Remove the tool, press the reset and try the disposal again.  If it jams again  remove any debris from the inside of the unit and then repeat the cranking procedure. If that doesn't solve the problem call me.

photo of disposal tool

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