Can two or more transactions sent from the same address be mined in the same block in Bitcoin's blockchain? Imagine a person Bob has 10 bitcoins in his wallet. He wants to send 5 bitcoins to Alice and another 5 bitcoins to Uncle Tom simultaneously (in separate transactions). Will both Bob's transactions be confirmed in the same block?

If yes, than consider the case when Bob sends all 10 bitcoins to Alice in one transaction and simultaneously issues another transaction to send Uncle Tom the same 10 bitcoins. How is the double spending problem prevented in this case (I would like a technical answer for this one)?
Will both Bob's transactions be confirmed in the same block?


This cannot be guaranteed. They might or might not.


  consider the case when Bob sends all 10 bitcoins to Alice in one transaction and simultaneously issues another transaction to send Uncle Tom the same 10 bitcoins.


Bob's wallet will not allow him to double-spend. If Bob circumvents this, one of the transactions will be rejected by the network. In the worst case there may be a short period where it is unclear which transaction will win.

Each node in the network, whether a miner or a wallet will verify incoming transactions and mined blocks and will reject any that attempt to spend TXOs that are not UTXOs - i.e. which that node knows are already spent. 

It can be that one miner selects the payment to Alice for inclusion in a block and another miner selects the payment to Tom. Other nodes will reject the second of such blocks that they receive, eventually the blocks with the most proof of work will be the only ones accepted, including by both miners.



Related questions:


How to return Tx to mem pool from orphan block
What&#39;s the longest chain of orphan blocks? (How many confirmations have been necessary?)
How is a blockchain split resolved?
Selfish Mining: stale or orphan?
Is there a correct way to refer to &quot;orphan&quot; blocks?


and 


What is an &quot;unspent output&quot;?