Electric Dryer doesn't start & hums when I press the Start Button?

Hello,

I have a Kenmore Electric Dryer, Model # 110.66901690.

My dryer doesn't start.
When I press the Push To Start button I get a hum (I figure it's from the motor) and a ticking noise behind the timer knob.

If I continue to hold the push to start button after a while the motor stops trying to work but the ticking behind the timer knob continues.

Other information that might help:
The drum moves freely when I push with my hands.

When I open the door, press the lever switch (Making the dryer door seem closed), and push to start button, I observe that the drum moves very slightly.

What is the problem?