阅读理解
　    Many people have to work on the weekend. Some people do not mind. Others think it is terrible.
　　One man thinks that working on the weekend can be dangerous. He is Graham Coates. Mr Coates works in an office in Brighton, England.
　　On Saturday, May 24, 1986, he went to the office to do some work. When he got on the lift(电梯), it stopped between floors. Mr Coates could not get out of the lift. He started to shout, but no one heard him. Then Mr. Coats remembered that it was a holiday in England. No one was going to come to work until Tuesday.
　　There was nothing for him to do. He had to wait until one of his workmates came to work and found him. With nothing to eat or drink, Mr Coats ended up sleeping for most of the day.
　　Now Mr. Coates says, "I only use lifts if they have telephones in them."

（1）地壳中含量最多的金属元素是____．

（2）生活中的钢铁制品通常是铁的合金，合金属于____ （填“混合物”或“纯净物”）．

（3）一般的导线由铜丝组成，说明铜有其良好的____性（填一条）．

（4）早在西汉时期，人们主要采用“湿法冶金”．如将铁浸入硫酸铜溶液中，该反应的化学方程式为____ ，基本反应类型为____ ．

小豪同学做了一个游戏，他将玩具小车放在地上启动，小车便开始做直线运动，然后小豪骑上自行车，在小车开出5s后出发全力去追小车，追上并超过小车后小豪适时进行刹车制动，停住后花1s时间下车随即刚好截住行驶的小车．已知小车启动后以加速度a=1m/s²作匀加速直线运动，达到最大速度v₁=5m/s便开始做匀速直线运动；而小豪骑车加速时的加速度为a₁=2m/s²，达到最大速度v₂=10m/s时也作匀速直线运动，在刹车制动时的加速度为a₂=5m/s²．试求：