I know I played this hand badly, no excuse but I had folded about 20-30 hand preflop before this one cause they were total trash ( i was a bit tilted by this hand. I know not good). I attempted to push him off the pot. After flop I still had str8 draw. My question is though how did my opponent make the calls he did with his hand? How could he have know his hand was good. I had just joined the table a few hands before? How much do I have to bet to get ppl to let go of trash?

Table "Basseterre" (real money) -- Seat 4 is the button
Seat 1: spam88 ($59.00 in chips)
Seat 3: enchanter ($110.50 in chips)
Seat 4: esolm ($34.75 in chips)
Seat 5: localcaddie ($74.00 in chips)
Seat 6: captainjoe79 ($115.25 in chips)
Seat 7: Ugly Ed ($40.25 in chips)
Seat 8: ckrockets21 ($36.75 in chips)
Seat 9: my_gem ($58.50 in chips)
Seat 10: mayhem29 ($154.75 in chips)
localcaddie: Post Small Blind ($0.50)
captainjoe79: Post Big Blind ($1)
Dealing...
Dealt to Ugly Ed [ Ah ]
Dealt to Ugly Ed [ Jd ]
Ugly Ed : Raise ($4)
ckrockets21: Fold
my_gem : Fold
mayhem29: Fold
spam88 : Fold
enchanter: Fold
esolm : Call ($4)
localcaddie: Fold
captainjoe79: Call ($3)
*** FLOP *** : [ Kh Ts 3s ]
captainjoe79: Bet ($5)
Ugly Ed : Raise ($10)
esolm : Fold
captainjoe79: Raise ($10)
Ugly Ed : Call ($5)
*** TURN *** : [ Kh Ts 3s ] [ 4h ]
captainjoe79: Bet ($13)
Ugly Ed : Call ($13)
*** RIVER *** : [ Kh Ts 3s 4h ] [ 5h ]
captainjoe79: Bet ($4)
Ugly Ed : Call ($4)
*** SUMMARY ***
Pot: $73.50 | Rake: $3
Board: [ Kh Ts 3s 4h 5h ]
spam88 didn't bet (folded)
McMulan didn't bet
enchanter didn't bet (folded)
esolm lost $4 (folded)
localcaddie lost $0.50 (folded)
captainjoe79 bet $36, collected $73.50, net +$37.50 (showed hand) [ 7c Kc ] (a pair of kings)
Ugly Ed lost $36 [ Ah Jd ] (high card ace)
ckrockets21 didn't bet (folded)
my_gem didn't bet (folded)
mayhem29 didn't bet (folded)