You are in a windowless car in an exceptikw /hqmw1n(clivk8* bdq38m (onally smooth train moving at constant velocity. Is there any physical experiment you can do in the train car to determine whether you are moving? Ex dl8i3q(*c81 mwvkn/bwqm( k hplain. ----待选择----yesno 

You might have had thesby93*p.d p4;v go w/c*bizuc experience of being at a red light when, out of the corner of your eye, you see ywb4p;3 c i*v /.pus 9b*odgczthe car beside you creep forward. Instinctively you stomp on the brake pedal, thinking that you are rolling backward. What does this say about absolute and relative motion?

A worker stands on top of a exsnja899x x se24 r9tmoving railroad car, and throws a heavy ball straight up (from his poxt a 48s29j9xr9e enxsint of view). Ignoring air resistance, will the ball land on the car or behind it?

Does the Earth really go around the Sun? Or is it also valid to sa *l.xnt;yo0- pik(mx iy that the Sun goes around the Earth? Discuss in view of the first principle olit i 0x;-pn*m( y.xkof relativity (that there is no best reference frame). Explain.

If you were on a spaceship traveling at 0.5c away frwgzzw -z(lk8wjjjp 2 v*1lz 41om a star, at what speed would the starlight pasklpjv (wzj - 2jzz *4gwl8zw11s you?

The time dilation ef78irndb9u* . owzewt4fect is sometimes expressed as “moving clocks run slowly.” Act. i9 b*84ue7odrntwwzually, this effect has nothing to do with motion affecting the functioning of clocks. What then does it deal with?

Does time dilation mean that time actually p n: lmnhi/w jq.ha80+masses more slowly in moving reference frames or that it only seems to pass more slowlyh8. /nqmahmlj :0wn i+?

A young-looking woman astronaut has just arrived home from a long ti e y1cp8yzn-8vhl3j6 rip. She rushes up to an1ic 8-6jyey8hl zpn3v old gray-haired man and in the ensuing conversation refers to him as her son. How might this be possible?

If you were traveling away from Earth at speed 0.5c, would you notice a chanri07af )lkv*m p+l4 rrge in your heartbeat? Would your mass, hevr0 ik* 4rpm) r+lafl7ight, or waistline change? What would observers on Earth using telescopes say about you?

Do time dilation and length contraction occur at ordinam-32th k* 0a xrs)gvzaiyg: 7vry speeds, say $90 \, \text{km/h}$?

Suppose the speed of light were infinite. What would happen to the relativi x(u mxz1mfsy2o. a:u0stic predictions of length contraction am10xuu m2x o:yf a(z.snd time dilation?

Discuss how our everyday lives would be different if the speed of light were -5bjbrcj q264zmdsfs4 r9 /vnonly6sj- mjcn frb95 r/2qvbd4z4s $25 \, \text{m/s}$.

Explain how the length contraction and time dilation formlj q+e) b2z y0.9cevo :rp,txdulas might be used to indicate that c is the limiting speeez+: ld2.rt,x09 voejb yc)q pd in the universe.

The drawing at the start of this Chapter shows the street as seen by Mr ;ldf(s2jrb 53esv jt. Tompkins, for whom the speed of sfsr l.(b2te5jdv; j3light is $c=20 \, \text{mi/h}$. What does Mr Tompkins look like to the people standing on the street? Explain.

  An electron is limited to travwbuh,l;,tk.*oui l z8b / ym0r2l oshwi15oo8 el at speeds less than c. Does this put an upper limit on the momentum of an electron? If so, what is this upper limit? If not, explai lui2wowlh5/t;lu okz 81h m,bsob* 8.ry ,o0in. ----待选择----yesno 

  Can a particle of nonzero rest mass attain the speadr :i2h:nuww z4u1d 5ed of light? ----待选择----yesno 

  Does the equation $E=mc^2$ conflict with the conservation of energy principle? Explain. ----待选择----yesno 

  If mass is a form of energy, does thisy7prg2nuoi 76*0 mpws mean that a spring has more mass when compressed tgom*wr upi2s 6y7p7 n0han when relaxed? ----待选择----yesno 

It is not correct to say that "matter can neither be created nor*hfj6r xgj: fr .zwq7. destroyed." What must wez*.. jrjfx7 hqr:fw6g say instead?

  Is our intuitive notion that velocities simply add, as we did in Section 3–eb2/i67xvutyz/vtu x ,v:l3y8, completely w6 v,t3l/bye yx2uvv/i z:7xturong? ----待选择----yesno 

  A spaceship passes you at a speed of 0.750c. You measure its lengthwhz ,j9hj;cm; to be 28.2 m. How long would it be when at rest? ;hm9jzc,h w;j $L_0$ =    m

  A certain type of elementary particle tr ,u-yzsqu ji+a.qx 4k)avels at a speed of $2.70 \times 10^8 \, \text{m/s}$. At this speed, the average lifetime is measured to be $4.76 \times 10^{-6} \, \text{s}$. What is the particle's lifetime at rest?
$\Delta t$ =    $ \times 10^{-6} \, \text{s}$

  Lengths and time intervalk26kvk6 wzmcay 2 )gz4s.22x3xuhd15b pb s wls depend on the factor $\beta = \frac{1}{\sqrt{1 - v^2/c^2}}$ according to the theory of relativity. Evaluate this factor $\beta$ for speeds of:
(a) $v = 20000 \, \text{m/s}$ (typical speed of a satellite); $\beta =$  
(b) $v=0.10c \;\; \beta =$  
(c) $v=0.20c \;\; \beta =$  
(d) $v=0.95c \;\; \beta =$  
(e) $v=0.98c \;\; \beta =$  
(f) $v=0.999c \;\; \beta =$  

  If you were to travel to a star 125 lighr9slmcf2wv*f 4 -2 cvbt-years from Earth at a speed of $2.50 \times 10^8 \, \text{m/s}$, what would you measure this distance to be? L =    ly

  What is the speed of a pion if its average lifetime iq6csicdl x7,g9wz 83ys measured to be $4.10 \times 10^{-8} \, \text{s}$? At rest, its average lifetime is $2.60 \times 10^{-8} \, \text{s}$. v =    c

  In an Earth reference fra+ )c-uk2u4gx,e 3o g*a z wvx:4edzupome, a star is 82 light-years away. How fast would you h v g ,d owxec)3a-4z24uupu:kez+*oxgave to travel so that to you the distance would be only 35 light-years? v =    c

  Suppose you decide to travel to a star 85 lig6(ephu-i cpz8+f f-ayht-years away at a speed that tells you the distance is only 25 light-years. How many years would it take you to m-u6f8ap- yf+ie (zchp ake the trip? t =    y

  At what speed $v$ will the length of a 1.00-m stick look 10.0% shorter (90.0 cm)? v =    c

  Escape velocity from the Earth yk6 9ii l)p-tee,* plcis $11.2 \times 10^3 \, \text{m/s}$. What would be the percent decrease in length of a 95.2-m-long spacecraft traveling at that speed? L =    $ \times 10^{-8}\%$

  At what speed $v$ do the relativistic formulas for (a) length and (b) time intervals differ from classical values by 1.00%? (This is a reasonable way to estimate when to do relativistic calculations rather than classical.) v =    c

  Suppose a news report stated that starship Enterprise had ju wjz s*9rr6,l0-opgelst returned from a 5-year voyagel lr0s-zpe*oj 6,r9gw while traveling at 0.84c.
(a) If the report meant 5.0 years of Earth time, how much time elapsed on the ship? $\Delta t_0$ =    yr
(b) If the report meant 5.0 years of ship time, how much time passed on Earth? $\Delta t$ =    yr

  A certain star is 10.6 light-years away. How long would it taken;7xxqzdkg+ *0dk:b z a spacecraft traveling 0.960c to reach that s+*kx zbx 0ngkzq:dd 7;tar from Earth, as measured by observers:
(a) on Earth, $t_{earth}$ =    yr
(b) on the spacecraft? $\bigtriangleup t_0$ =    yr
(c) What is the distance traveled according to observers on the spacecraft? L =    ly
(d) What will the spacecraft occupants compute their speed to be from the results of (b) and (c)? v =    c

  A friend speeds by you in her "Ferrari" spacecraft at a speedd) wvrs)rg ,0y5e(poy of 0.660c. It is measured in your frame to be 4.80 m long and (vs yred ,)p0)go 5ywr1.25 m high.
(a) What will be its length and height at rest?
$L_0$ =    m
the rest height is    m
(b) How many seconds would you say elapsed on your friend's watch when 20.0 s passed on yours? $\bigtriangleup t_0$ =    s
(c) How fast did you appear to be traveling according to your friend?    c
(d) How many seconds would she say elapsed on your watch when she saw 20.0 s pass on hers?   s

  How fast must an average pion be moving to tg (h8e/mbb (ntgl7 6h*rig(fgravel 15 m before it decays? The average lifetgmbgl/th gife((h * (67r8gb nime, at rest, is $2.6 \times 10^{-8} \, \text{s}$. v =    c

  What is the momentum ofoa+;q d-v15un xbee8z a proton traveling at $v =0.85c$? p =    $ \times 10^{-19} \, \text{kg·m/s}$

  At what speed will an object’s relativistic mass be 8yi *b9,bxo:6sv.whz*i gpdetwice its rest mass? v =    c

  A particle of rest mass tzvcixo6v,i. 5wvwgu /g ;w ::$m_0$ travels at a speed $v =0.20c$. At what speed will its momentum be doubled? v =    c

  (a) A particle travel)wq o76h/wmmn aqlp, 9s at $v =0.10c$. By what percentage will a calculation of its momentum be wrong if you use the classical formula?    %
(b) Repeat for $v=0.90c$.    %

  What is the percent change in momentum 7.q dtnm..bwk+v pkv9of a proton that accelerates
(a) from 0.45c to 0.90c,    %
(b) from 0.90c to 0.98c?   %

  A certain chemical ru;r8pw s)u*gk eaction requires $4.82 \times 10^4 \, \text{J}$ of energy input for it to go. What is the increase in mass of the products over the reactants?$\bigtriangleup m$ =    $ \times 10^{-13} \, \text{kg}$

  When a uranium nucleus at rest breaks apkct s0lh4sld -.)elx/k +bk4o art in the process known as fission in a nuks4 slcb-0k/ xhdt l4.e )k+loclear reactor, the resulting fragments have a total kinetic energy of about 200 MeV. How much mass was lost in the process? $\bigtriangleup m$ =    $ \times 10^{-28} \, \text{kg}$

  Calculate the rest energy of an electronu doy(n)2 1kw: bctyn2 in joules and in $\text{MeV}$ ($1 \, \text{MeV} =1.60 \times 10^{-13} \, \text{J}$).E =    $ \times 10^{-14} \, \text{J} = 0.511 \, \text{MeV}$

  Calculate the rest masyxau9 x )z2pb7s of a proton in $\text{MeV}/c^2$. $m_0$ =    Mev/$c^2$

  The total annual energy consumption in d x0fru(gag3 9 u*+,uxg7p zdqu2jh2othe United States is about $10^{19} \, \text{J}$. How much mass would have to be converted to energy to fuel this need?    kg

  How much energy can be obtained from conversion of 1.0 gram8qszg 62 6ifgbuf-pa* of mass?    $ \times 10^{13} \, \text{J}$How much mass could this energy raise to a height of 0.25 km above the Earth's surface?   $ \times 10^7 \, \text{kg}$

  What is the speed of a particle when its kinetic energ ye)r2zlwfr ;-y equals its rest energy? yw -rr;)lf2ezv =    c

  At what speed will an j p(l;see r(0bobject's kinetic energy be 25% of its rest energy? v =    c

  (a) How much work is required to accd* pa87lrn 8bqelerate a proton from rest up to a speed of 087 nq*rp dal8b.997c? W =    GeV
(b) What would be the momentum of this proton?p =    $ \times 10^{-18} \, \text{kg·m/s}$

  Calculate the kinetic energy and me4v9d/dp wj ()y-icqdomentum of a proton traveling $2.60 \times 10^8 \, \text{m/s}$.
KE =    $ \times 10^{-10} \, \text{J}$
p =    $ \times 10^{-18} \, \text{kg·m/s}$

  What is the momentum of a 750-MeV proton (that is, its kinrfzt:2m+4.spu:j9z* e awga cetic energy is 750 MeV)? 2gcr wzzj+*mu:p 4 e.fas9:ta   $\times 10^{-19} \, \text{kg·m/s}$

  What is the speed of a proton,me0u/qq y-vl accelerated by a potential difference of 105 MV? v =qe m-vylu/0, q    c

  What is the speed of an electron whose kinetic energy69sr ukku6m2tb k 6:uw is 1.00 MeV? v =    c

  What is the speed of an electron just before it hits a television screen after)y6j6 4nqy5celzjq 9 nua.s -i beinslz6iyuj jnq)4qye6-a c.95n g accelerated from rest by the 25,000 V of the picture tube? v =    c

Two identical particles opmelvt2 rgs(q:i5 )ys7 (9lb+qzye7gf rest mass $m_0$ approach each other at equal and opposite speeds $v$. The collision is completely inelastic and results in a single particle at rest. What is the rest mass of the new particle? How much energy was lost in the collision? How much kinetic energy is lost in this collision?

  Calculate the speed of mm )uk1.(bum-+ yf qc*b wiv0na proton ($m_0 =1.67 \times 10^{-27} \, \text{kg}$) whose kinetic energy is exactly half
(a) its total energy, v =    c
(b) its rest energy.v =    c

  What is the speed and the6v 37schwubi,-bn .n e momentum of an electron ($m=9.11 \times 10^{-31} \, \text{kg}$) whose kinetic energy equals its rest energy?
v =    c
p =    $ \times 10^{-22} \, \text{kg·m/s}$

  Suppose a spacecraft of mass 27,000 kg is accelerated to 0.21c*pbw l8,*zgzl .
(a) How much kinetic energy would it have? KE =    $ \times 10^{19} \, \text{J}$

(b) If you used the classical formula for kinetic energy, by what percentage would you be in error?    %

  Calculate the kinetic energy and momentum of akdcnf*w1 z*)-2g bhurnr4n4f proton ($m_0 =1.67 \times 10^{-27} \, \text{kg}$) traveling $7.35 \times 10^7 \, \text{m/s}$. By what percentages would your calculations have been in error if you had used classical formulas?
KE =    $ \text{MeV} \, $ with an error of    %
p =    $ \times 10^{-19} \, \text{kg·m/s}$ with an error of    %

  The americium nucleus, s a6 gfmwhy;fxvc(av/0xz q5a/ d:h83$^{241}\text{Am}$, decays to a neptunium nucleus, $^{237}\text{Np}$, by emitting an alpha particle of mass 4.00260 u and kinetic energy 5.5 MeV. Estimate the mass of the neptunium nucleus, ignoring its recoil, given that the americium mass is 241.05682 u. $m_{Np}$ =    u

  An electron ($m_0 =9.11 \times 10^{-31} \, \text{kg}$) is accelerated from rest to speed $v$ by a conservative force. In this process, its potential energy decreases by $6.60 \times 10^{-14} \, \text{J}$. Determine the electron's speed $v$. v =    c

Make a graph of the kinetic energy versus momentum for (a) a particle of nonzermw /g m/gnqjd . wxeuc6bt.195o rest mass, and (b.jte1 .q/wudx9 wcgmn/b6g5m) a particle with zero rest mass.

  What magnetic field intensity is ne zr9rg3ij 7jrxy/ 7 ju8(*dieweded to keep 998-GeV protons revolving in a circle of radius 1.0 km (at, say, the Fermilab synchrotron)? Use the relativistic mass. The proton's rest m7u (*x7 /dij jweji83zgryr9rass is $0.938 \, \text{GeV}/c^2$ ($1 \, \text{GeV} =10^9 \, \text{eV}$). [Hint: in relativity, it is still true that $\frac{mv^2}{r}=qvB$ in a magnetic field.] B =    T

  A person on a rocket traveling at 0.50c (with respect to the Eara31h - jp0ac d76j um-s2aigzbth) observes a meteor come from behind and pass her a-ib p2g60mjdah s3 7jacu-z1 at a speed she measures as 0.50c. How fast is the meteor moving with respect to the Earth? u =    c

  Two spaceships leave Earth in opposite directions, each with a speed of 0ryls +i0fe42j.50c with respec24es0yj il rf+t to Earth.
(a) What is the velocity of spaceship 1 relative to spaceship 2? u =    c
(b) What is the velocity of spaceship 2 relative to spaceship 1?u =    c

  A spaceship leaves Earth traveling at 0.71c. A secondyin i d t 5m+ xle4icqccn,p2v:+y*)e m(z/zx- spaceship leaves the first at a speed of 0.87c with respect to 4+cxymicmy ln2q5 +,cp-(e*i) x :/vntzei dzthe first. Calculate the speed of the second ship with respect to Earth if it is fired
(a) in the same direction the first spaceship is already moving, u =    c
(b) directly backward toward Earth.u =    c

  An observer on Earth sees an alienvylq( /kfs+;,uiwi 3kr*bp, k vessel approach at a speed of 0.60c. The Enterprise comes to the re* ii3vwf/;u(sqrpkl, k +k,ybscue (Fig. Below), overtaking the aliens while moving directly toward Earth at a speed of 0.90c relative to Earth. What is the relative speed of one vessel as seen by the other? u =    c

  A spaceship in distress sends out two escav qaw 5 g+bi7hr ;/u(9reef5ulpe pods in opposite directions. One travels at a se5uewv+/al qb(;9gr5fh7 uirpeed $v_1 =-0.60c$ in one direction, and the other travels at a speed $v_2 =+0.70c$ in the other direction, as observed from the spaceship. What speed does the first escape pod measure for the second escape pod? u =    c

  Rocket A passes Earth at a speed of 0.75c. At the same time, rocket B passe )lq4a x p;a-v +c7fxsx*:hkkvs Earth moving 0.95c relative to Earth in the same direction. How faa ;*q- sf7xx+ h :4calkv)xpvkst is B moving relative to A when it passes A? u' =    c

  The nearest star to Earth is Proxima Centauri, 4.3 light-years aways;yivdt6p4. c.
(a) At what constant velocity must a spacecraft travel from Earth if it is to reach the star in 4.0 years, as measured by travelers on the spacecraft?    c
(b) How long does the trip take according to Earth observers?$t_{Earth}$ =    yr

  As a rule of thumb, anything travelingvz:hm )v.z7gn faster than about 0.1c is called relativistic - i.e., for which the correction using special relativit.)v z mnv7gh:zy is a significant effect. Determine the speed of an electron in a hydrogen atom ($v \approx 2.2 \times 10^6 \, \text{m/s}$) and state if it is relativistic. (Treat the electron as though it were in a circular orbit around the proton.) ----待选择----relativistic not relativistic 

  (a) What is the speeo)kdklp3 : oo1d $v$ of an electron whose kinetic energy is 14,000 times its rest energy? You can state the difference $c - v$. Such speeds are reached in the Stanford Linear Accelerator, SLAC.    m/s less than c
(b) If the electrons travel in the lab through a tube 3.0 km long (as at SLAC), how long is this tube in the electrons' reference frame? [Hint: use the binomial expansion.]L =    cm

  How many grams of matter would have to be totally df;)( msofjpa1ofm8p(2. cr f mestroyed to run a 100-W lightbulb for 1 ymfo.pr m(cf ;1 smfp)aj2o f(8ear? $m_0$ =    $ \times 10^{-8} \, \text{kg}$

  What minimum amount of electromagnetic energy is needed to produce an eleth579vvvorem x. ;2l qctron and a positron together? A positron is a particle with the same rest mass as an electron, but has the opposite charge. (Note that e2 vqlvm xrh.o9et ;75vlectric charge is conserved in this process.) E =    MeV

  An electron ($m=9.11 \times 10^{-31} \, \text{kg}$) enters a uniform magnetic field $B=1.8 \, \text{T}$, and moves perpendicular to the field lines with a speed $v=2.5 \times 10^7 \, \text{m/s}$. What is the radius of curvature of its path? r =    mm

  A negative muon traveling at 33% th.ju c+ ddp.xd7e speed of light collides head on with a positive muon traveling at 50% the s7xd. +u j.pcddpeed of light. The two muons (each of rest mass $m_\mu = 105.7 \, \text{MeV}/c^2$) annihilate, and produce how much electromagnetic energy?E =    MeV

  A free neutron can decxj , 7ea.pnt4eg83s,tkw.pl aay into a proton, an electron, and a neutrino. Assume the neutrino's rest mass is zero, and the other masses can be found in the Table inside the front cover. Determine the total kinepg w 3t8neapl4j7exk.a t,.,stic energy shared among the three particles when a neutron decays at rest. KE =    MeV

  The Sun radiates energy at a ratehak1ks3v i t1i - ty3oxo7o73z of about $4 \times 10^{26} \, \text{W}$.
(a) At what rate is the Sun's mass decreasing?$\frac{\Delta m}{\Delta t}$ =    $ \times 10^9 \, \text{kg/s}$
(b) How long does it take for the Sun to lose a mass equal to that of Earth?$\Delta t$ =    $ \times 10^{15} \, \text{s}$
(c) Estimate how long the Sun could last if it radiated constantly at this rate.$\Delta t$ =    $ \times 10^9 \, \text{yr}$

  An unknown particle is 2ga imzkb*q4k y 9e7mqcpu.fhaa .++9measured to have a negative charge and a speed of $2.24 \times 10^8 \, \text{m/s}$. Its momentum is determined to be $1.07 \times 10^{-22} \, \text{kg·m/s}$. Identify the particle by finding its rest mass.
 ----待选择----electronpositron 

  How much energy would be required to otnbc96,s(,nnjw9 jv break a helium nucleus into its constituents, two protons and two neutrons? The rest masses of a proton (including an electron), a neuj9 6nno9jv wbs( tn,c,tron, and helium are, respectively, 1.00783 u, 1.00867 u, and 4.00260 u. (This energy difference is called the total binding energy of the $^4\text{He}$ nucleus.) KE =    MeV

  What is the percentage increase in the (relh+ 7-91e0(qb:nl vx cwrbibya ativistic) mass of a car traveling 110 km/h as compared tocy0 i+e1x-l r7aq:(hv bbnwb 9 at rest? [Hint: use the binomial expansion.]$\frac{\left(m-m_0\right)}{m_0}$ =    $\times 10^{-11}\%$

  Two protons, each having a spee7qhd1 f:rh+fed of 0.935c in the laboratory, are moving toward each othee +hf 17dhr:fqr. Determine
(a) the momentum of each proton in the laboratory, u =    $ \times 10^{-18} \, \text{kg·m/s}$
(b) the total momentum of the two protons in the laboratory,   
(c) the momentum of one proton as seen by the other proton.p =    $ \times 10^{-18} \, \text{kg·m/s}$

Show analytically that a particle with momentuma*h vp7i1dt )o h:d2ym $p$ and energy $E$ has a speed given by $v = \frac{pc^2}{E}$.

  The fictional starship Enterprise obtains its p48z4pw o- o4 ifeij ,tybkzrct8/dn-4ower by combining matter and antimatter, achievingz pno c48dr fk-iz8woit yb4t/j4,4-e complete conversion of mass into energy. If the mass of the Enterprise is approximately $5 \times 10^9 \, \text{kg}$, how much mass must be converted into kinetic energy to accelerate it from rest to one-tenth the speed of light?    $\times 10^7 \, \text{kg}$

  An electron is accelerated so that its kinetic energy is greater than its rs3mfbc2t- y:l8duyz, est mass d2:l yyfbz,suct8 3 m-$m_0c^2$ by a factor of
(a) 5.00, v =    c
(b) 999. What is the speed of the electron in each case?v =(1 -    $ \times 10^{-7}c$)

  A farm boy studying physics believes that he can fit a 15.0-m-long po 35h eu8yqngwf. +hb4jle into a 12.0-m-lo.eng+ju84 hb f35qyhwng barn if he runs fast enough (carrying the pole). Can he do it? Explain in detail. How does this fit with the idea that when he is running the barn looks even shorter to him than 12.0 m? ----待选择----possiblenot possible 

  When two moles of hydrogen and one mole of oxygen react to fo,/ri pr h1cw;grm two moles of water, the energy released is 484 kJ. How much does the mass of thpr 1 ;wgi,rh/ce elements decrease in this reaction?
$\Delta m$ =    $\times 10^{-12} \, \text{kg}$
What % of the total original mass of the system does this mass change represent?    $ \times 10^{-8}\%$

  In a nuclear reaction two identical particles are created, traveling in opposy(+ *qiv7 fifwxy5- ghdzs8-hite directions. If the speed of each particle is 0.75c, relative to the laboratory frame of reference, what is on5fd *izq-(78 gw yf+ yh-vhsixe particle's speed relative to the other particle? u =    c

  An astronaut on a spaceship traveling at 0.75c relabnj(hxh /1yt)tive to Earth measures his ship to be 25 m long. On the shipt1 hy/j x)n(bh, he eats his lunch in 23 min.
(a) What length is the spaceship according to observers on Earth? L =    m
(b) How long does the astronaut's lunch take to eat according to observers on Earth? $\Delta t$ =    min

You are traveling in a spaceship at a speed of 0.85c away from Earth. You seniy dv2otj0 , i2yu:hx*d a laser beam toward the Earth traveling at velocity c relative to you. What do observi22vhy*it:0j u d oy,xers on the Earth measure for the speed of the laser beam?

  A spaceship and its occupants have a total mass of 150,000 kg. The lhf t)vsc*gizy v6+8y:66qb boccupants would like to travel to a star that is 25 light-years ac 6 t+isq)vz:6*vb 8ygfyhbl6way at a speed of 0.60c. To accelerate, the engine of the spaceship changes mass directly to energy. How much mass will be converted to energy to accelerate the spaceship to this speed?    kg
Assume the acceleration is rapid, so the speed for the entire trip can be taken to be 0.60c, and ignore decrease in total mass for the calculation. How long will the trip take according to the astronauts on board?$\Delta t_0$ =   y

  Suppose a 12,500-kg spaceship left Ea9qb* 2jq1q8zp3kuwx4 uh :rscrth at a speed of 0.99c. What is the spaceship's kir1x9 83k*sju4bqqwhupc:zq 2netic energy? Compare with the total U.S. annual energy consumption (about $10^{19} \, \text{J}$). KE =    $ \times 10^{20} \, \text{J}$

  A 42,000-kg spaceship i o7 eu .5iymgwx/dms)9s to travel to the vicinity of a star 6.0 light-years from Earth. Passengers on the ship want the (one-way) trip to take no more than 1.0 year. How much work must be done on the spaceship to bring it to the speed necessary for this tr.dime)yg/7 m95 owxusip? u =    c

  A 1.68-kg mass oscillates on the end of a spring whoc;:tqk s1+ kzfse spring stiffness constant i;1q:f kkc t+szs $k=48.7 \, \text{N/m}$. If this system is in a spaceship moving past Earth at 0.900c, what is its period of oscillation according to
(a) observers on the ship, T =    s
(b) observers on Earth? $T_{earth}$ =    s

A pi meson of rest ma:qq6l7fsy9c qs cot)zr98; td:h/ u bvss $m_\pi$ decays at rest into a muon (rest mass $m_\mu$) and a neutrino of negligible or zero rest mass. Show that the kinetic energy of the muon is $KE_\mu = \frac{(m_\pi - m_\mu)^2 c^2}{2m_\pi}$.