You are in a windowless car in an exceptionally sm:a 4x qp/a8ykeooth train moving at constant velocity. Is there any phyx4:aq kaye /p8sical experiment you can do in the train car to determine whether you are moving? Explain. ----待选择----yesno 

You might have had the experience of being at a red li;gu b/9,ct60rsjs6e 6wd cfiight when, out of the corner of your eye, you see the car beside you creep forward. Instinctively you stomp on the brake pedal, thinking that you are rci09uf ,/r6 ;idtw6secb sj6golling backward. What does this say about absolute and relative motion?

A worker stands on top of a moving railroad car, and throws a heavy ball s (t ;t9rv5nfjktraight up (from his poinf nj9rv5kt (;tt 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 v( pd )is(bp6iealid to say that the Sun goes around the Earth? Discuss in views)iibedp( (6p of the first principle of relativity (that there is no best reference frame). Explain.

If you were on a spaceship traveling at 0.5c away from a stv lb0y7: du5 ytdj63ypar, at what speed would the starlight pasld0up3y5 7ytbdv6:yj s you?

The time dilation effect is sometimes expressed as “moving clocks run slowly.” oebv2a 4iez .18bwut d/s 5s5iActually, t5 1 v8s5a2i b eoedi/4zb.twsuhis effect has nothing to do with motion affecting the functioning of clocks. What then does it deal with?

Does time dilation mean thax -9mdu4 ztl+bt time actually passes more slowly in moving reference frames or that it oxbd9ltu +z4-m nly seems to pass more slowly?

A young-looking woman astronaut has just arrived; secz.ow9rawy0k,.m4nly p. home from a long trip. She rushes up to an old gray-haired man and in the ensuing conversation refp s; lzm4o r0a,.k.wwec y9yn.ers to him as her son. How might this be possible?

If you were traveling away frv)-o+a7jh mt(0z uiu eom Earth at speed 0.5c, would you notice a change in your heartbeat? Would your mass, height, or waistline change? What would observers on Earth using telescope+z0a-ot m)7 uhuij (ves say about you?

Do time dilation and lengtkgn dz4,z r34qgbem 57h contraction occur at ordinary speeds, say $90 \, \text{km/h}$?

Suppose the speed of light were injziv :a)prk88 finite. What would happen to the relativistic predictions of length contraction and ti8)ri kap8:vz jme dilation?

Discuss how our everydl/ txe04e6 ur+2rw. igs(asjnclt)c;ay lives would be different if the speed of light were onll.r;xgstl (4uc ce a2t+rj/ n0e6)w siy $25 \, \text{m/s}$.

Explain how the length contractifaaay2)(ttcat8 .v. con and time dilation formulas might be used to indicate that c is the limiting speed in the tacyata)at f . 82cv.(universe.

The drawing at the start of this Chapter shows the street: ia)k*gh:3axk k7aop as seen by Mr Tompkins, for whom the speed of:gakokhx) :3ik7 a*ap light 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 travel at speeds less than c. Does this puqbaj my q 5g90o3yh:)xt an upper limit on the momentum of an electron? If so, what is this upper limit? If noty3mqya:jx5o0 gb 9 )hq, explain. ----待选择----yesno 

  Can a particle of nonzero rest ma,g2f+m+ grac vss attain the speed 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 this mean that a sprivetn9*ljq:w y 2tya vfq0;(0hng has more mass when compressed than when(wyeq:hl09;y*f 0atv 2jntvq relaxed? ----待选择----yesno 

It is not correct to say that "matter can neither be5-p() ntrxjs x created nor destroyed." What must we say n- (px)5 tsrxjinstead?

  Is our intuitive notion that velocities simply add, 2u:/3 cyrueug as we did in Section 3–8, completely wro/ 3guru:yc2eu ng? ----待选择----yesno 

  A spaceship passes you at a speed of 0.750c. You measure it2iu+is k5w*bot4wq 3bs length to be 28.2 m. How long would it be whq4ii5* bw2+ twokub 3sen at rest? $L_0$ =    m

  A certain type of elementary partic 4sjdm(ir1b 9f4in+( f vbc+tele travels 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 intervk11*32z ,ft i iupufsw8q9b jfals 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 light-years from Earth at a spwn o f0yn53:0bdz/ .3mzkshpoeed 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 is measured to bed qg8v hi(qtn004p 7my9je. /9qo tlpf $4.10 \times 10^{-8} \, \text{s}$? At rest, its average lifetime is $2.60 \times 10^{-8} \, \text{s}$. v =    c

  In an Earth reference frame, a star is 82 light-years awao/s 2(/k1otsn u*odpsqo)7n g y. How fast would you have to travel so that to you the distance would be only 35 light-year/ 2odn) sg(s7ostk*/1po qonus? v =    c

  Suppose you decide to bq6mi e-ud84 ko7:leqtravel to a star 85 light-years away at a speed that tells yo8qdube 6 iem-ko7l:q4 u the distance is only 25 light-years. How many years would it take you to make 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 thirt(j .zxqvm:uc v83e l/z z60e Earth is $11.2 \times 10^3 \, \text{m/s}$. 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 star;c x;0rk97+q csiixl dt,-ut eship Enterprise had just returned from a 5-year voyage while traveling at 0.cq +7t;ltks,cxi9 - ri;dxeu084c.
(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 take a4 ,gzg/ 3ejool l2zu6zog p/w+ spacecraft traveling 0.960c to reach that star from Earth, as measured by oblw26gz4 l/po/go o3zugje+ ,zservers:
(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" spacecrnbs(n ) jtt4opdc mj;b+6moe01g7.c4p /u be raft at a speed of 0.660c. It is measured in your frame to be 4.80 m long and 1.25 m h( pbmt7ojb1necdcur ;./s 4 e mb 6)+4tpognj0igh.
(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 pbt y;jadr85 fkm2 /8vjion be moving to travel 15 m before it decays? The average lifetime, at rryt akd885fm jvj2; b/est, is $2.6 \times 10^{-8} \, \text{s}$. v =    c

  What is the momentum oigf59i6 zn kw;mq xq9)1w t.tif 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 twiceds ar;c u7kx:q:m97u h its rest mass? v =    c

  A particle of rest mass ohrjqm (lh8n kkzo.pd6:w0 + +$m_0$ travels at a speed $v =0.20c$. At what speed will its momentum be doubled? v =    c

  (a) A particle travels nubtdq fdj3 mt3a 8 -ypk);3d.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 -bc:e5 yup11rlbn6n)7 yxvqn o(hc e.in momentum of a proton that accelerates
(a) from 0.45c to 0.90c,    %
(b) from 0.90c to 0.98c?   %

  A certain chemical reaction requires qt2egc( )bm2gjb)daed l; 7k8$4.82 \times 10^4 \, \text{J}$ 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 apart in the proceskd3.y)i 3jaxos known as fission in a nuclear reactor, the resulting fragments have a total kinetic energy of about 200 MeV. How much mass was lost in t3.xa 3ijkdo)y he process? $\bigtriangleup m$ =    $ \times 10^{-28} \, \text{kg}$

  Calculate the rest energy of an electron in joules a ruv)j9* ceei-w ;qo:end 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 mass of a proton in 4iowv8-wucjhl: *6rc$\text{MeV}/c^2$. $m_0$ =    Mev/$c^2$

  The total annual energy consumption in the U: t ;b)bngv*icnited 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 )0+ icg4 g9 m:sbzf ohm:)qdutof 1.0 gram 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;nq.df) ev-qqkr .c:e energy equals its rest energy? ve-qr; f.qdve:)nqkc . =    c

  At what speed will an object's kinetic energy be 25% of its rest / hm n/f-v*81( fd+m8;xvlz:fw t/lwzp btjakenergy? v =    c

  (a) How much work is required to accelerate a proton from rest upa (opia s k6p05.uwjc+ to a speed of 0koua(s pacj6i w0.5+p.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 momentum of a pro nl3(mozgkypx)6 7v; zton 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 kinetic energk;f9. ghu* szlkg zd-6y is 750 MeV)?dhkuk-g g; z69fz*.ls    $\times 10^{-19} \, \text{kg·m/s}$

  What is the speed of a proton accel:t0 i hhj5bqb6erated by a potential difference of 105 MV? v =iqbhb5htj 60 :    c

  What is the speed of an electron whose kinetic eneapdd)iv 9owvwt;7isx ,p+myhh:1r79rgy is 1.00 MeV? v =    c

  What is the speed of an electron just before it hits a nel9s8b9cyg4p o 6y -ytelevision screen after being accelerated from rest by the 25,000 V of the picture tube? v6oyb yn p sy99e8-lgc4 =    c

Two identical particles of rest mass j2.q m tt 1fs*9f3vhlh$m_0$ 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 a n b+uzbu+epwau2(52r* kudj4 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 the momen yw.nm1op))k; n/9 l76ini abfg:gwbutum 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.czg mt2puyl :e9phc qc84 59z521c.
(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 and6vo, jc:k.aa m momentum of a 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 nucleuqp4f( )l( :nqtrtm:1ygg zu ,is, $^{241}\text{Am}$, 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 p1)n3g /qsf2kqht7q bj m3 i5goarticle of nonzero rest mass, and (b) a paq j3/t 3 bi7qgk)o1ms2q g5fhnrticle with zero rest mass.

  What magnetic field intensity is needed to keep 998-GeV protons revolving in a copqbaa4 9hkkp6ji 0/ *ircle of radius 1.0 km (at, say, the Fermilab synchra*6ppq ki k9oba4hj0/otron)? Use the relativistic mass. The proton's rest mass 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 respesg 9ks. x/b;-cnil hgl2p9 vy:ct to the Earth) observes a meteor come from behind and pass her at a spg.ks y;nh2bs9g9xl/lv: c -pi eed 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 wy)tsok91rqo-; e 0h)(tn)9gxxe17nvw pnw jdith a speed of 0.50c with respect to Ear09q)xnw )hxr ) pv(tesgwj79ke-n 1dnt1 yoo;th.
(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 second )x7.shv h 4pbf i)qq.vt 4*ysaspaceship leaves the first at a speed of 0.87c with respect to the first. Calculate the speed of the second shis4.ipv7hfsxtq.y) qv * ) ha4bp 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 alien vessel approach at a, ng0 wt2sxmt) speed of 0.60c. The Enterprise comes to the rescue (Fig. Below), overtaking the aliens while moving directly toward Earth at a speed of),0wxnmtg 2ts 0.90c relative to Earth. What is the relative speed of one vessel as seen by the other? u =    c

  A spaceship in distress send p,wp.so it2y 9oxg21rs out two escape pods in opposite directions. One travels92x rg .o1pti,y wo2sp at a speed $v_1 =-0.60c$ 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, rockett g (6rlgpl wp-,m)z-n B passes Earth moving 0.95c relative to Earth in the same direction. How fast is B moving relative to A when it passeszg pwg(mtr , 6)-llpn- A? u' =    c

  The nearest star to Earth is Proxima Centauri, 4.3 light-years a )etnnb(a axiin4v:4r r0pd --way.
(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 traveling faster than about 0v890 bpl0a- bucpgy(x .1c is called relativistic - i.e., for which the correction using special relabl u8g 09yvcbp0xa-(ptivity 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 speedfhb.)bec8evyu-g;i x k*mbm 7:3,ylh $v$ 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 destroyed to run *s(.. hvomr-.yb fe oia 100-W lightbulb for 1 year b(fyv.i .mo-.osh*re? $m_0$ =    $ \times 10^{-8} \, \text{kg}$

  What minimum amount of electromagnetic energy is needed to produce an electroh psj846mn 6whaptos33ii u7/n and a positron together? A positron is a particle with the same rest mass as an electron, but has the opposite charge. (Note that electric chargesn 736p4a8uiow 6ts h/3mi hjp 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 )rz gg7j-zk5t 33% the speed of light collides head on with a positive muon traveling at 50% the speed of light. The two muon5 ) zkgzgr7jt-s (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 decay into a proton, an electron, and a neutrino. Assume ibir)a, gr.f 85k/au lthe neutrino's rest mass is zero, and the other masses can beiu fal8, agrr kb5./i) found in the Table inside the front cover. Determine the total kinetic energy shared among the three particles when a neutron decays at rest. KE =    MeV

  The Sun radiates energy at a rate of a8ga/f/ba . dz7/7*k nqlrz zdlbout $4 \times 10^{26} \, \text{W}$.
(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 measu6jqxh 6e4 n7fered 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 break a helium nucleus into ir3f)vq,l vl gk)gn j90ts constituents, two protons and two neutrons? The rest masses of a proton (including an electron), a neutron, and helium are, respectively, 1.00783 u, 1.00867 u, and 4.00260 u. (This energy difference is cl9qr),l)kgfgn 0 3jv valled the total binding energy of the $^4\text{He}$ nucleus.) KE =    MeV

  What is the percentage increase in the (relativistic) mass of h-(;v ynhsy*y a car traveling 110 km/h as compared to at rest? [Hint: use the bin y*-nhv;ys( hyomial expansion.]$\frac{\left(m-m_0\right)}{m_0}$ =    $\times 10^{-11}\%$

  Two protons, each hauon+jey oik1bu)j )d :)gj.q y9yh h74ving a speed of 0.935c in the laboratory, are moving toward each otu:b j)7.kny)u 4) ohqdhjo +j1igy y9eher. 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 wbp+qpme jqx6 8z 30rt6ith momentum $p$ and energy $E$ has a speed given by $v = \frac{pc^2}{E}$.

  The fictional starship Enterprise obtains its power by combininrqf ,)cwhy3 ch .;zmaher)/ l6g matter and antimatter, achieving complete conversion of mass into energy. Ile/3w hczrah6;qrm .ch,y) )ff 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 itslz7/sx uvq.hm drgt + c11*pn- kinetic energy is greater than its rest masnhrg*1xv 1t-+zq7 d/ pusm l.cs $m_0c^2$ 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-y,i4:nw8g -v5.ca zxk6u ;fi , (wem-rkmawtulong pole into a 12.0-m-long 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 runnikr (ki5aum,v w,xue w6c.4azn8 g w-y:t-m; fing 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 reacjjjp4 .-w jck5cljq06t to form two moles of water, the energy released is 484 kJ. How much does the mass of the elements decrease ikj jc.-pjc04j 5j qwl6n 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 cr;;,u6z2 vl(uo *pyb g;tlwzggeated, traveling in opposite directions. If the speed of each particle is 0.75c, 2b u*;tugzly go (6 ;zgw;vlp,relative to the laboratory frame of reference, what is one particle's speed relative to the other particle? u =    c

  An astronaut on a spaceship traveling at 0.75c relative to Earth j18je u0v1sc. jg1vnz measures his ship to be 25 muvgcj0.1 evj1 j18snz long. On the ship, 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 spa4t2vw cs :1pqcceship at a speed of 0.85c away from Earth. You send a laser beam toward the Earth traveling at velocity c relative to you. What do observers on the Earth measure for the speed of the laser beapt swvc1q24c: m?

  A spaceship and its occupants have a to 95iu.ivyv6r/h/xj:cas 0r sstal mass of 150,000 kg. The occupants would like to travel to a star that is 25 light-years away at a speed of 0.60c. To accelerate, thessjvui/ c/hix :5rv.yrsa06 9 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 Earth at a speed of)c* et;hm*ro9e kw x+o 0.99c. What is the spaceshiphx; ktro)*ow 9mc+*ee's kinetic 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 is to v /r3rxu/xnj6e: ; zhumzm t51travel 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 doxu 3tu :/rnz5x /6zr1hj;emv mne on the spaceship to bring it to the speed necessary for this trip? u =    c

  A 1.68-kg mass oscillates on the end of a spring whose spring eofk3.q7lq ( moc-4y/n g8ttf stiffness constantyf8moq.n3ft/l(4-g 7tokecq is $k=48.7 \, \text{N/m}$. 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 mass g4wz jwxqes 05v /wo/4-.ousl $m_\pi$ 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 $KE_\mu = \frac{(m_\pi - m_\mu)^2 c^2}{2m_\pi}$.