正确回答三道就可以给分Question 1.How many people are talking on their cell phones at this instant?Question 2.How large a moon can you jump off of?In other words,assuming reasonable densities,what is the radius ofthe largest rocky sphere fr

正确回答三道就可以给分Question 1.How many people are talking on their cell phones at this instant?Question 2.How large a moon can you jump off of?In other words,assuming reasonable densities,what is the radius ofthe largest rocky sphere fr
正确回答三道就可以给分
Question 1.How many people are talking on their cell phones at this instant?
Question 2.How large a moon can you jump off of?
In other words,assuming reasonable densities,what is the radius of
the largest rocky sphere from which you can reach escape velocity
by jumping?Estimate your answer within a factor of 10.
Question 3.Acceleration
Estimate and compare the accelerations of a) a jet airplane taking
off,b) a car accelerating to highway speed,and c) a person starting
on a walk.
Question 4.Stop the World,I Want to Get off
If every human ran for 10 seconds as fast as possible to the east,
by what fraction would they change the Earth’s angular velocity
around its axis (while they were running)?
Question 5.Automobile kinetic energy
Compare the kinetic energy of a car driving on the highway with
the chemical energy required to keep driving for one minute and for
one hour.What fraction of the chemical energy is ‘lost’ to friction
and air resistance (i.e.,to thermal energy)?Use an energy density
for gasoline of 3 107 J/L.
1
Question 6.Neutron Stars
The Sun rotates on its axis once per month.If the Sun shrinks and
becomes a neutron star,by what factor will its rotational inertia
change?What will its new period of rotation be?(Note:the
density of the Sun today is approximately 103 kg/m3.)
Question 7.Solar Mass Loss and Orbits
As the Sun converts hydrogen to helium through nuclear fusion,it
emits energy.This decreases the mass of the Sun and changes the
orbits of all the planets.How much lighter will the Sun be when
it completes the hydrogen burning phase?By how much will this
change the orbit of the Earth?Give your answers in numbers and
in percent.
Question 8.Drifting Continent Momentum
What is the momentum of a drifting continent?(Estimate this
in the reference frame of the Earth; i.e.,ignore the rotational and
translational motion of the Earth.) How does this compare to a
supertanker or aircraft carrier at top speed?
Question 9.Dynamic Range of the Eye
What is the dynamic range of the human eye?In other words,
what is the ratio of the maximum power that can be seen without
damaging the eye to the minimum power that can be perceived?
(Hint:The energy of one photon is given by E = h_,h is the planck
constant.)
Question 10.Satellite Data
Google Maps currently supplies satellite photographs of Earth with
a resolution of a few meters.How much disk space is needed to store
all that data?If they improve the resolution to 1 cm,how much
more disk space will be needed?How much data transmission rate
will be needed if they update the photographs annually?
Question 11.Lecture Hall:Mass of Brain vs Mass of Air
Compare the mass of air with the mass of brains contained in the
typical lecture hall.

正确回答三道就可以给分Question 1.How many people are talking on their cell phones at this instant?Question 2.How large a moon can you jump off of?In other words,assuming reasonable densities,what is the radius ofthe largest rocky sphere fr
I'm Professor Gu Wei Hua from SJTU JI.
It is not allowed to search for answers on the internet.It's against the Honor Code and I will find you and punish you.

无语了，这啥玩意嘛
先翻译出来，过会答
问题1 。有多少人在谈论他们的手机在这个瞬间？
问题2 。多大的月亮可以跳下的？
换言之，假设的合理密度，什么是半径
最大的岩石领域，从中可以达到逃逸速度
跳？估计您的答案在10倍。
问题3 。加速度
估计和比较加速度a ）在喷气飞机采取
后， b ）在加快公路汽车的速度...

全部展开

无语了，这啥玩意嘛
先翻译出来，过会答
问题1 。有多少人在谈论他们的手机在这个瞬间？
问题2 。多大的月亮可以跳下的？
换言之，假设的合理密度，什么是半径
最大的岩石领域，从中可以达到逃逸速度
跳？估计您的答案在10倍。
问题3 。加速度
估计和比较加速度a ）在喷气飞机采取
后， b ）在加快公路汽车的速度，和c ）一个人开始
上散步。
问题4 。停止的世界，我要下车
如果每个人都跑10秒尽快以东，
由哪些部分，他们会改变地球的角速度
围绕其轴（而他们运行） ？
问题5 。汽车动能
比较动能汽车在高速公路上驾车与
化学能源必须保持驾驶一分钟，并为
一个小时。哪些部分化学能是'失去'摩擦
和空气阻力（即热能） ？使用能量密度
汽油的3 107焦耳/研究
1
问题6 。中子星
太阳旋转，其轴心每月一次。如果太阳收缩和
成为一个中子星，由什么因素将其转动惯量
变化？什么将其新的时期的轮换呢？ （注：
太阳的密度大约是103今日kg/m3 。 ）
问题7 。太阳质量损失和轨道
太阳转换氢氦的核反应，它
排放的能源。这一跌幅是太阳质量的和变化的
轨道上的所有行星。多少打火机将太阳的时候
它完成了氢燃烧阶段？由这需要多少
改变地球的轨道？给您的答案号码和
在百分之。
问题8 。大陆漂移动量
什么是动力的漂流大陆？ （估计这
在参照系地球，即忽视了旋转和
平移运动的地球。 ）有何比较了
超级油轮或航空母舰上的最高速度？
问题9 。动态范围的眼
什么是动态范围，人眼的？换句话说，
什么是比的最大功率，可以看到不
损害眼睛的最低功耗，可感知？
（提示：在一个光子的能量是通过E = h_ ， h是普朗克
常数。 ）
问题10 。卫星数据
谷歌地图目前供应的地球卫星照片与
决议几米。多少磁盘空间来存储需要
所有这些数据？如果他们改善决议1厘米，有多少
更多的磁盘空间，将需要？多少数据传输速率
将需要更新，如果他们的照片，每年？
问题11 。演讲厅：大众脑与空气质量
比较大规模的空气质量的大脑中载
典型的演讲厅。

收起

what is your meaning？？

温热我玩过

...你在show你的英文吗？

sorry , i can not nuderstand!