問題詳情:
已知:c=10,且a,b滿足(a+26)2+|b+c|=0,請回答問題:
(1)請直接寫出a,b,c的值:a= ,b= ;
(2)在數軸上a、b、c所對應的點分別為A、B、C,記A、B兩點間的距離為AB,則AB= ,AC= ;
(3)在(1)(2)的條件下,若點M從點A出發,以每秒1個單位長度的速度向右運動,當點M到達點C時,點M停止;當點M運動到點B時,點N從點A出發,以每秒3個單位長度向右運動,點N到達點C後,再立即以同樣的速度返回,當點N到達點A時,點N停止.從點M開始運動時起,至點M、N均停止運動為止,設時間為t秒,請用含t的代數式表示M,N兩點間的距離.
【回答】
(1)a= -26,b=-10;···············································································(2分)
(2) AB=16;AC=36;·····················································································(4分)
(3)①當0≤t≤16時,MN=t,
②當16<t≤24時,MN=t-3(t-16)=-2t+48,
③當24<t≤28時,MN=3(t-16)-t=2t-48,
④當28<t≤30時,MN=36×2-t-3(t-16)=-4t+120,
⑤當30<t≤36時,MN=4(t-30)=4t-120,
⑥當36<t≤40時,MN=3(t-16)-36=3t-84.···
知識點:有理數的乘方
題型:解答題