第一章
1.1
原子的大小是?
What is the approximate size of an atom?
m
1.2
下面哪個人可能觀察到不符合牛頓第一定律的現象？
Which of the following people might observe somethingthat appears not to agree with Newton's first law ofmotion?
Aperson riding a roller coaster (過山車)
1.3
向量<-2, 7, 3>的大小是多少?
Whatis the magnitude of the vector <-2, 7, 3>?
7.87
1.4
下列哪個表述是無意義的？
Whichof the following expressions is not meaningful?
< 1,7,-2 > - 5
1.5
<3, 3, 3>的單位向量是?
What is the unit vector in the direction of <3, 3,3>?
< 0.577 , 0.577 , 0.577 >
1.6
一個質子在位置A，一個電子在位置B，怎樣計算從質子到電子的動量?
A proton is at location ,and an electron is at location . How would youcalculate the vector that goes from the proton to the electron?
- （向量B減向量A）
1.7
以宿舍大門為原點，43秒時你的單車位置在<3,0,20> m, 48秒時，你單車的位置在<2, -3, 35> m. 求你單車的平均速度？
Atthe time 43 seconds after 8am, your bicycle is located at <3,0,20> m,relative to an origin at the front gate of your dormitory (宿舍). At the time 48 seconds after 8am, your bicycleis located at <2, -3, 35> m?
< -0.2 , -0.6 , 3.0 > m/s
1.8
51秒時你的單車位置在<2,-4,40> m，此時此刻其速度為<0, -0.5, 4> m/s，求51.5秒時單車的心理陰影面積位置？
At the time 51 seconds after 8am, your bicycle is located at <2, -4, 40> m.Its velocity at that moment is <0, -0.5, 4> m/s. What is the position ofthe bicycle at 51.5 seconds after 8am?
< 2 , - 4.25 , 42 > m/s
1.9
The position of an object is described by a vector , as a function of time. Which of the followingexpressions gives the instantaneous velocity of the object?
（←紅色）
1.10
Suppose the position of an object at time t is.What is the acceleration of the object at time t = 0?
< 0 , 0 , 4 > m/s
1.11
What is the momentum of a proton traveling at a velocity of m/s?[The mass of a proton is kg.]
kg·m/s
1.12
As you turn a corner on your bicycle, you move from location A to location B, asshown in the figure.
What is the direction of , the change in momentum between these two locations?
←
第二章
2.1
Which of the following statements is correct?
Newton's 2nd Law can be written as
2.2
1.As you turn a corner on your bicycle, you move fromlocation A to location B, as shown in the figure.
What is the direction of , the change in momentum between these twolocations?
←
2.It took 1.5 seconds for the bicycle to move from A toB. weight of the bicycle is 20kg, the bicycle's velocityis < 20, 7.5, 0 > m/s at A and < -10, 7.5, 0>m/s at B. What was the net force acting on the system during this timeinterval?
< -400 , 0 , 0 > N
2.3
An electron is moving through space at a speed closeto the speed of light. At one instant in time, its momentum is kg m/s. It experiences an electric force of N. After a time of 3 ns ( s), what is the new momentum of the electron?
kg m/s
2.6
You throw a basketball across the court with aninitial velocity of m/s. After 0.4 seconds, the velocity is m/s. What is the best choice for the y-component ofthe average velocity during this time interval?
1.05m/s
2.8
An object hanging from a spring (彈簧)will oscillate (震動) up and down. You perform anexperiment on a particular mass-spring system, and observe that it oscillatesonce every 3 seconds. Which of the following would not be agood choice for , if you used a computer to predict the motioniteratively?
1s
2.12
A car traveling at 20 m/s crashes into a wall, coming toa complete stop. After the crash, the car is 50 cm shorter than before. Abouthow long did the collision（碰撞） last? (In other words, how muchtime passed between the car first touching the wall and finally stopping?)
0.05s
TEST
1. Which of the following can NOT be true for anobject moving in a straight line at a constant speed?
The object is experiencing a net interaction.
2.A bee flies in a straight line at constant speed. At 15 safter 9 AM, the bee's position is < 2, 4, 0> m. At 15.5 s after 9 AM, thebee's position is < 3, 3.5, 0> m.
What is the average velocity of the bee?
< 2.000, −1.000, 0 > m/s
3.At 12.18 s after 1:30 PM, a ball's position is <20, 8, −12>m, and the ball's velocity is < 9, −4, 6 > m/s.
What is the (vector) position of the ball at 12.21 safter 1:30 PM?
Assume that the ball's velocity does not changesignificantly in this short time interval.
< 20.27, 7.88, −11.82 > m
4.Three protons travel through space at threedifferent speeds.
Proton A: 290 m/s
Proton B: m/s
Proton C: m/s
For which proton(s) is it reasonable to use theapproximation when calculating its momentum?
A and B
5.Anobject is moving in the +x direction. Which of the following statementsabout the net force acting on the object could be true?
A.The net force is in the +x direction
B.The net force is in the –x direction
C. The net force iszero
A and B and C
6.Cart（小推車） A moves to the left at nearlyconstant speed. Cart B moves to the left, gradually speeding up. CartC moves to the left, gradually slowing down.
Which cart(s) experience a net force to the left?
B only
7.Youpush a book across a table. In order to keep the book moving with constantmomentum, you have to keep pushing with a constant force.
Which statement explains this?
To make the net force on the book zero, you must pushwith a force equal and opposite to the friction（摩擦） force on the book.
8.Two running students collide（撞） head-on. One student exerts（用/施加） a force of magnitude F on the other student. Suppose wechoose BOTH students as the 「system」 to which to apply the momentum principle.What is the net force acting on this system?
< 0, 0, 0 >
9.Aball is initially on the ground, and you kick it with initialvelocity < 3,7,0> m/s. At this speed air resistance isnegligible（可忽略的）. Assume the x axis（軸） is to theright, the y axis is up, the z axis is out the screen.
Which components of the ball's momentum will change inthe next half second?
py
10.The mass of the ball is 500 g, and its initialvelocity is < 3,7,0> m/s. What is the net impulse acting on the ballduring the next 0.5 seconds after you kicked it?
B. < 0, –2.45, 0 > N*s
第三章
3.1
Touch the table in front of you with your hand. The forcethat you feel with your hand is due to which fundamental interaction?
electromagnetic
3.2
The gravitational force exerted by a planet on one of its moons is 3e23 newtons when the moon is at a particular location. If the mass of themoon were three times as large, what would the force on the moon be?
9X1023
3.3
Distance from star to planet: m
Star’s mass: kg
Planet’s mass: kg
N·m2/kg2
Calculate the magnitude of the gravitational force thatthe star exerts on the planet.
1.34X1022N
3.4
The Earth has a mass of kg. The Sun is much moremassive; its mass is kg. Which of the following statements is correct?
The gravitational force on the Sun by the Earth is exactly the same in magnitudeas the gravitational force on the Earth by the Sun.
3.5
The mass of Mercury is eleven over two hundred the massof earth, and the Mercury radius is eight over twenty-one of the earth, is theg on Mercury larger or smaller than on earth?
smaller.
3.6
Whicharrow best indicates the direction of the net electric force on the bluenegatively charged object?
7
3.7
A sodium ionexerts a force of 3e–8 N on a proton that is a distance d away. If the sodium ion were moved to a distance 3d from the proton, what wouldthe magnitude of the force on the proton be?
0.33e–8 N
3.8（兩道題是一樣的）
A bullet of mass 0.04 kg traveling horizontally at aspeed of 800 m/s embeds itself in a block of mass 0.5kg that issitting at rest on a very slippery sheet of ice. You want to find the speed ofthe block just after the bullet embeds itself in the block. What should youchoose as the system?
the bullet and theblock
3.9 && 3.10
When a pingpong ball collides with a bowling ball, why is the effect on the ping pong ballmore noticeable than the effect on the bowling ball?
The change inthe bowling ball’s velocity is less than the change in the ping pong ball’svelocity.
P.S.
3.9的字幕在附件中
第四章
4.1
A spacesatellite of mass 500 kg has velocity < 12, 0, –8 > m/s just before beingstruck by a rock of mass 3 kg with velocity < –3000, 0, 900 > m/s. If wechoose the space satellite and rock to be system, and just after the collision, themomentum of the system will be
the same.
4.2
As it shows inthe vedio, there are two blocks, the mass of bolck1 is 4M and block2 is 2M. thedistance between two blocks is r. The center of mass is
close to block1.
4.3
What objects exert significant forces on the red block?
Earth, String 1, String 2
4.5
You push a 100 kg mass on the floor with a horizontalforce, and it’s moving in the direction you are pushing at a constant speed. Thecoefficient of static friction is 0.3. How much force are you exerting onthe block?
294N
4.6
1. A ball hangs fromthe bottom of a vertical spring. You pull the ball downwards and release it,and the ball oscillates up and down. At the bottom of each oscillation, where theball’s instantaneous momentum is zero, what is the direction of the change in themomentum of the comet?
Up
2.Whichof the red arrows labeled 1, 2, or 3 represents the vector , the change in the momentum of the comet?
3
4.7
The red arrow shows the rate of change of the comet'smomentum when it is at location 2.
At this instant,which components of are zero?
Neithercomponent
4.9
Tarzan swings from a vine. At the bottom of the swing,which components of are zero?
Theparallel component
4.10
Tarzan swings from a vine. At thebottom of the swing, what is the direction of the net force acting on Tarzan?
1
4.11
At the bottom of the swing, how doesthe magnitude of the force on Tarzan by the vine compare to the magnitude ofthe force on Tarzan by the Earth?
F vine > F Earth
4.12
Tarzan swings from a vine.Tarzan'smass: 100 kg. Length of vine: 5 m. Tarzan's speed: 13 m/s. What is the tensionin the vine at this instant?
4360N
TEST
1.
Fixed starposition: < 0.5e11, 1e11, 0 > m. Initial planet position: <2e11, 1.5e11, 0 > m. Calculate the vector that points from the star to theplanet.
< 1.5e11, 0.5e11, 0 > m
2.
Mass of Mars: 6.4e23 kg; radius of Mars: 3.4e6 m
Mass of Earth: 6e24 kg; radius of Earth: 6.4e6 m
If the Mars rover measured the value of g on Mars, it would be:
less than 9.8 N/kg
3.
An alpha particle contains two protons and two neutrons,and has a net charge of +2 e.
The alpha particle is 0.1 m away from a single proton,which has charge + e.
Which statement about the magnitudes of the electricforces between the particles is correct?
The force on the proton by thealpha particle is equal to the force on the alpha particle by the proton.
4.
The mass of one atom is m (kg/atom). The density of solid copper is r (rho)(kg/m3). What is the volume occupied by one atom of copper in asolid?
m/ r
5.
You push an initially stationary 100 kg mass on the floorwith a horizontal force. The coefficient of static friction is0.6. What is the minimum amount of force you need to exert on the mass in orderto get it to move?
588N
6.
You push a 100 kg mass on the floor with a horizontalforce of 400 N, and it’s moving in the direction you are pushing. Thecoefficient of static friction is 0.3. What happens to the speed of theblock while you push it?
The speed increases
7.
Here is an incomplete force diagram for the system of thered block.
To complete it we need to draw theforce due to String 1. Which arrow best indicates the direction of this force?
8
8.
F1 and F2 aremagnitudes of forces.What is the unit vector in the direction of the force ?
< cos(90+q), cos(q), 0 >
9.
F1 and F2 aremagnitudes of forces.
Which equation correctly states thatdpx/dt = Fnetx?
0 = F1*cos(90+q) + F2
10.
The Moon travels in a nearly circular orbit around theEarth, at nearly constant speed. When the Moon is at location A, which components of are approximate zero?
The parallel component