1)
Why was Elisha angry? How should Yo'ash have known to strike more?
1.
Rashi: He should have realized that Elisha made him hold the bow for a Siman of salvation
1
.
2.
Radak: Yo'ash should not have ceased shooting
2
until Elisha told him to stop.
1
And the same applies to striking arrows on the ground. (PF)