chem about metals easy

1.D
2.D(titanium is very corrosion resistant,it won't react with the fluid in our body)
3.D
4.C
5.D(same as Q1?)
6.A(what is the difference between Q1,5 and 6?=.=)

2012-02-29 18:36:15 補充：
SOR ,the answer of Q2 should be A

2012-02-29 18:56:02 補充：
the characteristics of titanium:
light,strong,corrosion resistant,malleable
water tap and artificial hip joint should be made from corrosion resistant material.

2012-02-29 18:56:12 補充：
While bicycle frame should be made from some light materials
A light material requires less force to achieve for a same speed compared with a heavier material,it is not difficult to understand

2012-02-29 18:56:24 補充：
By KE=1/2mv^2,two bicycles with same velocity may have different KE,as their mass may be different from each other.Hence,the KE of the bicycles at same speed may not be equal.

2012-02-29 18:56:37 補充：
More chemical energy from our body needs to be transferred to kinetic energy of the bikes to reach the same velocity for the bike with larger mass.

2012-02-29 18:56:41 補充：
By W=Fs,energy transferred increases,displacement equal(because the velocities are same),F increases.
The force applied by the driver thus increases if a heavier material is being used.

Therefore,the answer should be option B.

2012-02-29 19:43:18 補充：
sor-.- option A

2012-02-29 19:59:35 補充：
sor,should be option A,
typing mistakes..

2012-02-29 21:18:06 補充：
But I don't think titanium will be used in making missile after analysing its properties.
The question asks which of the following objects is "least likely" to contain titanium.Although water tap and bicycle frame may not be made from titanium in the real situation,it is possible.

2012-02-29 21:18:10 補充：
Hence I think the answer should be A.

2012-02-29 23:05:29 補充：
thx,I just can't think that how could the properties of titanium be applied on a missile.

2012-03-01 17:36:27 補充：
thx for your correction,
the answer of Q2 should be B

Q2 should be B.
as a < > metal, application on fixed object is a waste. copper / plastic is good enough to do the job.
(case of) missiles should light (and strong), so that it can fly fast / carry more explosives.

Q2 is nonsense= ="
who will use titanium to make water tap and bicycle frame?
it's a waste of material!

2012-03-01 17:33:20 補充：
titanium can be used to make the outer layer of missiles since it is light and corrosive resistant,
you can use titanium to make water tap if you feel angry that you have too much money.It should be the least likely way to use titanium!