一条英文数学题目~求各位帮帮忙解答

来源：百度知道 编辑：UC知道 时间：2024/05/22 01:16:15
1)A bicyclist makes a trip that consists of three parts, each in the same direction(due north) along a straight road.During the first part, she rides for 22 minutes at an average speed of 7.2 m/s. During the second part, she rides for 36 minutes at an average speed of 5.1 m/s. Finally, during the third part, she rides for 8.0 minutes at an average speed of 13 m/s.

a) how far has the bicyclist traveled during the entire trip?

b)what is her average velocity for the trip?

可以的话请留过程~谢谢~

一个单车手将要完成一个分三段的路程, 每段都沿一条直路, 向同一个方向(北)走。第一段她以平均7.2m/s的速度走了22分钟。第二段她以平均5.1m/s的速度走了36分钟。最后, 第三段她以平均13m/s的速度走了8.0分钟。问:
(A) 她整个路程一共走了多远?
(B) 她整个路程的平均速度是多少?

解:
(A) s总 = v1t1 + v2t2 + v3t3 = 7.2 * (22 * 60) + 5.1 * (36 * 60) + 13 * (8.0 * 60) = 26760(米)
(B) v平均 = s总 / t总 = s总 / (t1+t2+t3)
= 26760 / [(22 + 36 + 8) * 60]
= 6.76(米/秒)