How long walk track 3 to track 16

We arrive to Tokyo Station at 9:11 AM on Track 3 on the JR Musashino line From Tokyo Disney.We depart Track No.15 SHINKANSEN HIKARI 509 to Takayama at 9:33 AM. We will have luggage with us.How long does it take to walk,and how difficult is the transfer(steps,elevators?)with luggage.Is it possible to reach Shinkansen in 15 or 20 min? If we miss it, we have to wait for 1 hr for the next one.We plan to reach Takayama early afternoon.We have already purchased JRPasses and will validate them at Narita upon our arrival.Any suggestions would really help.Thank you very much.

It takes about 10 minutes. But if you are unfamiliar with the station and have lots of luggage, it could take 15 minutes. The platforms of the Musashino/Keiyo Line are far away from the rest of the station. But apart from the distance it is no problem with luggage thanks to the availability of escalators.

If you travel with much luggage, I recommend expecting at least 15 minutes for a transfer from a Keiyo Underground track to a Tokaido Shinkansen track in Tokyo Station.
(Living along JR Keiyo Line, I have made transfers in Tokyo Station many times from Keiyo Line to another JR Line, but I suppose 10 minutes may be too short even for me.)

We arrive to Tokyo Station at 9:11 AM on Track 3 on the JR Musashino line From Tokyo Disney.　
We depart Track No.15 SHINKANSEN HIKARI 509 to Takayama at 9:33 AM.
We plan to reach Takayama early afternoon.

You are thinking of a wrong Shinkansen train.
According to the current timetable, the Tokaido Shinkansen train departing at 09:33 from Tokyo is HIKARI 507, which is scheduled to use Track 16.
Takayama is not served by Shinkansen. It is about 2 and a half hours on a Ltd. Express train from Nagoya.

[Transfer in Tokyo from a Keiyo Underground track to a Tokaido Shinkansen track]
Note
: If you take a train in Maihama Station at a car near its tail, you will be closer to escalators for Yaesu pathway in Tokyo Station.
: Tracks in Tokyo Station for trains from Maihama are Keiyo Underground Tracks 3 - 4 on the 4th basement, not Tracks 3 - 4 on the ground.
: A Shinkansen icon for Tokaido and San’yo Shinkansen is often drawn on a blue background.
http://commons.wikimedia.org/wiki/File:Shinkansen_blue.png
- Map of Tokyo Sta. of JR
http://english.jr-central.co.jp/info/station/_img/tokyo_L.jpg
(1) You can use two escalators upward to Yaesu pathway, which is mostly omitted in the above station map.
(2) On Yaesu pathway you can either walk all the way or partly use three moving walkways, where it is recommended to make the right-half way for passengers who hurry.
(3) From the end of Yaesu pathway you can use an escalator upward to the concourse.
(4) Please pay attention to names of Shinkansen lines. (JR-Central and JR-East have Shinkansen zones separately in Tokyo and their Shinkansen Transfer gates are located close.)
(5) You can find Shinkansen South Transfer Gate for Tokaido and San’yo Shinkansen of JR-Central, which is shown with No. 9 in the above station map. (You should show your Japan Rail Pass to an attendant at the gate.)
(6) After passing through the transfer gate, you can use an escalator or an elevator to your Shinkansen platform.

NOT: Shinkansen South Transfer Gate for Tokaido and San'yo Shinkansen of JR-Central
BUT: Shinkansen South Transfer Gate (of JR-Central) for Tokaido and San'yo Shinkansen

In Tokyo Station, there are many signs in phrases and icons. All you will have to do there are to follow signs for Tokaido Shinkansen, to show your Japan Rail Pass at the transfer gate, to go up to the correct platform and to ride your Shinkansen train at the correct car.