题干

2011年7月1日,南平九峰山脚下“自锚式独塔悬索斜拉”的跨江大桥投入使用,这座大桥主线桥梁全长449m,双向六车道.一辆小车匀速过桥时的速度如图所示.(结果保留一位小数)求:

(1)该小车的行驶速度为多少km/h?合多少m/s?

(2)小车以此速度通过主线桥需多长时间?

上一题 下一题 0.0难度 选择题 更新时间:2018-12-03 05:47:26

答案(点此获取答案解析)

解:
(1)由图知:速度表的分度值为:5km/h,因此所示的轿车速度为:40km/h=40×
1
3
.
6
m/s≈11.1m/s;
答:小车的速度是40km/h,合11.1m/s.
(2)小车需要的时间为t=

同类题3

阅读理解

    Papa's jaw dropped when Mama told him that Sister had cheated on her final exams—not to succeed but to fail. “It's unbelievable!” he said. “Sister has always been so proud of her good grades!”

    “Yes, she has,” said Mama. “But it's not unbelievable. It just shows how badly she wanted off the swimming team.”

    “Wanted off the swimming team?” said Papa. “She never said anything about that to me.”

    “Of course she didn't,” said Mama. “She was afraid you'd blow your top. You already had her getting a swimming scholarship to college and winning gold medals at the Olympics. Can you imagine how much pressure she must have felt? For her, being on the team couldn't have been much fun.”

    “Oh, my god!” Papa said, clapping a hand to his forehead. “I've been so stupid! I just thought she'd want to be a champion swimmer because she's so good at it.”

    “It's like anything else, dear,” said Mama. “No matter how good at it you are, if it stops being fun, you won't want to do it anymore.”

    Papa put his head in his hands.

    “She must be really mad at me,” he mumbled. “Maybe I should say sorry to her.”

    Sister's footsteps could be heard on the stairs. She came into the kitchen and looked hopefully up at her parents.

    “Honey,” said Mama with a smile, “your papa and I have decided that there's no reason for you to be on the swimming team if you don't want to.”

    Sister's face lit up like a Christmas tree. “Yippee!” she cried.

    “And,” added Papa, “there's no need for any more drills. I'm sure you'll bring your grades back up all by yourself.”

    Sister ran to Papa and jumped into his arms. She gave him a big hug. “I'm going to go play cards with Lizzy!” she said. “See you later!”

    From the kitchen window, Mama and Papa watched their daughter run down the sunny road toward Lizzy's house.

    “It's good to see her happy again,” said Mama.

    “It sure is,” Papa agreed. “As for the swimming team, there's always next year.”

    “If?” Mama prompted him.

    “Oh, right,” said Papa. “If she wants to.”

    Mama smiled. “At least you're learning, dear,” she said. She kissed him.

    “Well, you know what they say,” Papa said. “Better late than never.”