You are in a windowless car in an exceptionally smooth train moving at consudr/5;a-tuc 48:i, ebu(3jupcpb y pstant velocpup y uturce,bub:c8j5-d/a s;4i( p3ity. Is there any physical 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 light -gqly, ys5o77 euo saa;dd.;uwhen, out of the corner of your eye, you see the car beside you s o5d;; ou.ag7,ue 7q-y asldycreep 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 moving railroad car, and throws a k2k;egeg1p2 gh 47iioheavy ball straight up (from his point of view). Ignoring air resistance, will the ball land on the car or bgi2 27ei kg 1k4eh;gpoehind it?

Does the Earth really go around ttqi 7rm;dn)x3p8p6/ tl4b p6n ,skusmhe Sun? Or is it also valid to say that the Sun goes around the Earth? Discuss in view of the firstb n,i;nlts8m/km dsp4 u)p3 pt66xr7q principle of relativity (that there is no best reference frame). Explain.

If you were on a spaceship traveling at 0.5c away from a star, at wz5mqvc + 03j gdabo-yc53kwy:hat speed woulwzjmc353g qb5v +0 yo ckd-:yad the starlight pass you?

The time dilation effect is sometimes express -5iiyp2b5 (oe +dhktccwfm-8ed as “moving clocks run slowly.” A 5hcb2pyf+(m5ico 8-deikt -wctually, 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 passes more slowly i; fr3c08cpd mon moving reference frames or t d;mro 38fpcc0hat it only seems to pass more slowly?

A young-looking woman astronaut has just arriveye ;e54j;twy vd home from a long trip. She rushes up to an old gray-haired man and in the ensuing conversation refers to him as her son. jw; e; ty5ey4vHow might this be possible?

If you were traveling away from Earth at speed 0.5c, would you notgku)l l57jo4v:k. dc kice a change in your heartbeat? Would your mass, height, or waistline change? What would observers on Earth using telu.ok:c) kldj l4g k57vescopes say about you?

Do time dilation and length contraction occur+(4kw*g9r sw vvqyf3e at ordinary speeds, say $90 \, \text{km/h}$?

Suppose the speed of light were infinite. What would happenc u4f+f6vhp rt*8zf 7a to the relativistic predictions of length contraction and tt pvfh6rca4uz+ f87*fime dilation?

Discuss how our everyday lives would be differentr)ckr7rxpb e26 2x13kk,s aw x if the speed of light were only , k 2r1bkpr7 a36xrwk)x e2xcs$25 \, \text{m/s}$.

Explain how the length contract4pxx f/ 55fifa3zi4zo ion and time dilation formulas might be used to indicate that c is the limiting speed iia pi44ffxo3z5f/xz5 n the universe.

The drawing at the stawg,p fkz z-e:3- gqur)b91h icrt of this Chapter shows the street as seen by Mr Tompkins, for whom the speed of light isfbg)iw 1 uk - z3ehq,zr9c-g:p $c=20 \, \text{mi/h}$. What does Mr Tompkins look like to the people standing on the street? Explain.

  An electron is limited t qrejf;s mq:7:o travel at speeds less than c. Does this put an upper limit on the momentum of an electron? If so, what is thj ;7em qfsr:q:is upper limit? If not, explain. ----待选择----yesno 

  Can a particle of nonzero rest mass attainc1b7w4 doya e3 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 tc8w5 pk0h2l auhat a spring has more mass when compr hw8apk05l c2uessed than when relaxed? ----待选择----yesno 

It is not correct to say thpt 5gmmf,1yo wqd1tws4: -9myat "matter can neither be created nor destroyed." What ms1o1 ,y g tdmw5y :fmm-4pqtw9ust we say instead?

  Is our intuitive notion that velocities simply add,. 1x2xhe ue4rm4+eook as we did in Section 3–8, completely 2h4eor+ xeuk ex.4o1 mwrong? ----待选择----yesno 

  A spaceship passes you at a speed of 0.6 kigw tuzeb ;b;7ugqph1s)34 5-d hqi750c. You measure its length to be 28.2 m. How long would iu)i4hgp sz-;kg7 ubqieq dw1b;365h tt be when at rest? $L_0$ =    m

  A certain type of elementary pa)4,ufu o kws,crticle 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 intervals depex1e ;utda,b)w nd 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 lightvw 68 *dkq nd9ospkw03-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 itso;r(7pjwz9 jbi1*bh h average lifetime is 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 frame, a star is 82 light-yearspi7l3)od fq 8x away. How fast would you have to travel so that to you the distance wo3 f87oldxiq) puld be only 35 light-years? v =    c

  Suppose you decide to traol+ tu:8 nv i9up1(iwovel to a star 85 light-years away at a speed that tells you the distance is only 25 light-years. How many years would it take you to make the trip? t =1 + t8ip9i :lovuno(wu    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 Ezlvgm cc/z 6/,6tud/aarth 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 th)zlhpc)e g0* pat starship Enterprise had just returned from a 5-year voyage while traveling a0plezchp) ) *gt 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 longwa d2fpbexbl7 14ukt2s4q 7 0s would it take a spacecraft traveling 0.960c to reach that star from Earth, as measured by obse2 d4spkbt7q0sbxu 72l1w4fea rvers:
(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 sdqscg t.10h) m gekxyduy:3:1hxb . n7peed of 0.660c. It is measured in your frame to ).7bc.:gye xquh 3t:0hn yd kg1ms 1dxbe 4.80 m long and 1.25 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 travel 15 m before it decays? T;-oxbte xs3akcl;g /8he average lifetime, at rest, i8;3 xc-lek abt/xsg; os $2.6 \times 10^{-8} \, \text{s}$. v =    c

  What is the momentum of a proton trave4* nz5,g9).aah+xn-s*r xj bhids unpling at $v =0.85c$? p =    $ \times 10^{-19} \, \text{kg·m/s}$

  At what speed will an object’s relativistic mass be twic1roy) po7pk57k9(b,doocm q bkyy3g/ e its rest mass? v =    c

  A particle of rest ma;3e1 csznm sdy bj qw5gn2:w(:ss $m_0$ travels at a speed $v =0.20c$. At what speed will its momentum be doubled? v =    c

  (a) A particle travely0k f(hz x1r-m zj3q5xra0 zt/s 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 cha jdjd0+ 50u0,qntrkh(5 duo,ducnyn* nge 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 rew06ii0 7s zcw )db5xpvquires $4.82 \times 10^4 \, \text{J}$ 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 process known as fission i :2ye m+qmv kn,+-kruln a nuclear reactoqumnv +rek:-,k 2ly+mr, 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 energnw7 7kyy +ti7hy of an electron 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 masmxl 7)bdq-y6 es of a proton in $\text{MeV}/c^2$. $m_0$ =    Mev/$c^2$

  The total annual energy consumption in the Uru nopb41(rc4 7ya9kb* 9a8 zfv b9qijnited 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 conm1n )cf( o e8rx9bf6p(nd nb9pw6d6cbversion of 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 kinetiec j 8,nl/asa1c energy equals its rest energy? v =n/a 1aj8cse,l    c

  At what speed will an object's kinetic energy be 25% of its peno3n02cly0a ub( ,gdh14l qrest energy? v =    c

  (a) How much work is required to accelerate a proton from rest up to a sp8awx:u0 r,c f: e hs/ytb2nyr1eed of 0.9:, y1/ns8af2r0urw:tecbhy x 97c? W =    GeV
(b) What would be the momentum of this proton?p =    $ \times 10^{-18} \, \text{kg·m/s}$

  Calculate the kinetic energy and momentu7a vemxhh,:m3m 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 o8r:rp+r(xo tjf a 750-MeV proton (that is, its kinetic energy is 750 MeV p:xrrjo+8 r(t)?    $\times 10^{-19} \, \text{kg·m/s}$

  What is the speed of 7 /-sa6ehe azma proton accelerated by a potential difference of 105 MV? v = m6a hsze/7-ea   c

  What is the speed of an elevkg d09iw+ r,actron whose kinetic energy is 1.00 MeV? v =    c

  What is the speed of an electronzm j0crlsfdm u whsq72 b;z2-h;67i x,rt+d2o just before it hits a television screen after being accelerated from rest by the 25,000 V of the pictu0+wflc; bsh2z- 7sjmz2;rmhi 27dr dx ,6tqoure tube? v =    c

Two identical particlesj 7;jt(u 9eakp of 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 ofj9 i9rq+ 4nr ic..boy4q aprk -5y*ftnmseo, 1 a 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 anqjcf -u,ps //8 6ykpttd the 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 accele7jwvbdgaui-j 1 qwu;2 5+ iy:orated to 0.21c.
(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 1jb4m)uf-i ybmomentum 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 nucleusldqul4sma59z1hu9 g40;kq s l, $^{241}\text{Am}$, 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 pascr;/ja + vl1*c, pvgn*-vldhrticle of nonzero rest mass, and (b) a particle w j s,r; *lvav/cdv- n*+hlgc1pith zero rest mass.

  What magnetic field intensity is needed to keep 998-GeV protons revolving in a crxoe3 yb6/o-o u- u t.2:qpcyzircle of radius 1.0 km (at, say, the Fermilab synchrotron)? Use the relativistic mass. The proton's r:t/uxe b o py23u-ooz -cq6.yrest 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 respect to thewd9yh jm f-+ ;w:-0jvzobyo8vjn +xy* Earth) observes a meteor come from behind and 9+z:0 ;fyyd-+wv b y8jx howjjm-o*nvpass her 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 withlvp9*88 cl nlo a speed of 0.50c with respect 89no8vl*lp cl 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 second spa34 lbo:8ec4wcr it3eqceship leaves the first at a speed of 0.87c wc:r4ocq8l 43b eeti3with respect to the 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 alien vessel approach at a speed of 0.6;fp np-ooj gntk+es6 8m s.,6pk(/l rp0c. The Enterprise comes to the rescue (Fig. Below), overtret p;+g- kjo,m6okp/n8.fnsl p( sp6aking 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 sendf0r8ysp 5q-wds out two escape pods in opposite directions. One travelssfyd 0w-5p 8qr 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, rocket B )95zvr)olukk passes Earth moving 0.95c relative to Earth in the same directionl )kv59kur o)z. How fast is B moving relative to A when it passes A? u' =    c

  The nearest star to Earth is Proxima Centauri, ek6i tt*a5;+-fuhgqy4.3 light-years away.
(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 try5xn,gech q2qd( v+l t1+o5ahaveling faster than about 0.1c is called relativistic - i.e., for which the correction using special relativity is a significant effectn5 o215 elcgaqvq x(++,dthyh. 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 speeo5j e 07u, ssfe)aehrx-f3 qh)d $v$ 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 destroyedw:h h,wrqo/2 z to run a 100-W lightbwzh 2/hq,wr: oulb for 1 year? $m_0$ =    $ \times 10^{-8} \, \text{kg}$

  What minimum amount of ele5cu 3fvf y*(kbctromagnetic energy is needed to produce an electron and a positron together? A positron is a partic*k(yu c3ff v5ble with the same rest mass as an electron, but has the opposite charge. (Note that electric 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% the speed ofbr tx 7wre/7by x1tn(2 light collides head on with a positive muon traveling at 50% the speed of li/2wx b(7 t brxn7t1reyght. 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 decay into a p x4i( f. a/,j kq5kb6leri)1bbxo:urkroton, 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 kinetic energy shared among the three particles when a neutron decays at rest.1fr4xbku( i kibx 5e6:.l/b k)o,qjr a KE =    MeV

  The Sun radiates energy at a rjdll b: 43.3x0b ejxrtate 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 measured to have a negative charge and a sp8:dhod a. wai.eed 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 requir dk *1v2jt(x,a ifns1red to break a helium nucleus into its constituents, two protons and two neutrons? The rest masses of a proton (including an electron), a neutro(a dtsnjiv f* r11x,k2n, 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 (relativisl6tgb+:ue zwf4 r ds2 u(fn5vy+av5+ptic) mass of a car traveling 110 kt nf5rydg+v fv2 s64bp5wau+ zl:ue+(m/h as compared to at rest? [Hint: use the binomial expansion.]$\frac{\left(m-m_0\right)}{m_0}$ =    $\times 10^{-11}\%$

  Two protons, each having a speed of 0.935c in the laboratory, are moving toqfq9io: a)5 wsward each ot9qf5o)qw is:aher. 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 or7 ng i3nt1sfv* j993hbk eq(particle with momentum $p$ and energy $E$ has a speed given by $v = \frac{pc^2}{E}$.

  The fictional starship Enterprise obtains )ft6mxwbe+b s,v 7-)vp4 kgetft)ls7its power by combining matter and antimatter, achieving complete conversion of mass into energy. If the xfmt)e -v7ws47bvs+t6bep k ,ltg )f) 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 ff(n*m .im qqu)oai+c .lb w;6than its rest mmq ;b 6uoi.acq+.)n wflf(m i*ass $m_0c^2$ 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 physic;zesbr s8r z 39tqz6/ts believes that he can fit a 15.0-m-long 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 th8;be 6/qstzs9rzrz3t at 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 form two m:glly4 v7i-d 55ob3ee 4x tqjnoles of water, the energy released is 484 kJ. How much does the mass of the ele5qnjd3eyl4:5o tebx-7v g4il ments 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, tt .v8ao* p: b89f)rjf)zmgwg:s:htkoraveling in opposite directions. If the speed of each particle is 0.75c, relative to the laboratory frame of reference, what is one particle's speed :*:)oorv8bwt8.p kh j9g)szftmgf: a relative to the other particle? u =    c

  An astronaut on a spaceship traveling at 0.75c relative to Earth measures hisf907qo. cte6- d, wiopdm2lpc ship .fo9p0p6c dmole,7 tqc2- diw to be 25 m 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 spaceshi ;of+(0b)vf oh5tvbrop at a speed of 0.85c away from Earth. You send a las)o v0 hv5 to+(fbob;frer beam toward the Earth traveling at velocity c relative to you. What do observers on the Earth measure for the speed of the laser beam?

  A spaceship and its occupants have a total mass of 150,000,xh+.xqtmyx +17oc iz kg. The occupants would like to travel to a star that is 25 light-years away at a soxqxiy7tmx. c1 + z+,hpeed 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 Earth at a s w0 m7xjni3o.vpeed of 0.99c. What is the spaceship's kinetic energy? Compare with the total U.S. annual energy consumptionm o7ij. xnv30w (about $10^{19} \, \text{J}$). KE =    $ \times 10^{20} \, \text{J}$

  A 42,000-kg spaceship is to travel to the vicinity of a star 6.0 l/vlow1o4an 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 spa/woa01nl lov4 ceship 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 springcn/svj 1 :stq,l;1wv,3o heo wkf-f6d stiffness constant is 1-k3:ood hf vl,cfn6vejtww;s/,s1q$k=48.7 \, \text{N/m}$. 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 m-qiuzcwdmkbhda)3sy .y:41 oam729 jass $m_\pi$ 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 $KE_\mu = \frac{(m_\pi - m_\mu)^2 c^2}{2m_\pi}$.