You are in a windowless car in an exceptionally smooth train moving 6dq g4l9 ug:9gyiqj y8at constant velocity. Is there any physical experiment you can do in the train car to determine whether you are moving?l4u6 qg:gd9qyj9g 8iy Explain. ----待选择----yesno 

You might have had the expefoqax53t,t4 x;x wzi4rience of being at a red light when, out of the corner of your eye, you see the car beside yq54z4;w f3t ax xto,xiou 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 moving railroad car, and throws a heavy ball straigamkrm)c7y3hyggz- v7wc.0,i ht up (from his point of view). Ignoring air resistance, will the ball land m-c7)yg m30ichz yvg. k7raw,on the car or behind it?

Does the Earth really go qqjb 2m76 h3tcyu2hl:around the Sun? Or is it also valid to say that the Sun goes around the Earth? Discuss in view of yt :7qbcujh262 l3mhqthe first principle of relativity (that there is no best reference frame). Explain.

If you were on a spaceship trav : g6djrd z;tkw71s /m9(qtjqveling at 0.5c away from a star, at what speed would the starl(qv/dg;6wdsj7 j9 1tzmkqr:t ight pass you?

The time dilation effect is sometimes exiwd hin4g3 6d9pressed as “moving clocks run slowly.” Actually, this effect has nothing to do with motion affd i 6wng9hdi34ecting the functioning of clocks. What then does it deal with?

Does time dilation mean that time ac8 ;g wahf9/3 /ol3op zsaxdo/gtually passes more slowly in moving reference frames or that it onl / ozpa98; gdaxos3f//3olghwy seems to pass more slowly?

A young-looking woman as, 1kx3g5 umf(q3wmtgv tronaut has just arrived 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.v5tgqm3wmk,g1( f3x u How might this be possible?

If you were traveling away from Earth at speed 0.5c, would you notice a c4m0,v:i rtcidha 9 ua5*djt4jhange in your heartbeat? Would your mass, height, or waistline change? What would observers on Earth using teles9* 04dajmiad,u ci h:v4t5rtjcopes say about you?

Do time dilation and length contractioeny+z i/27+apnnw e -on occur at ordinary speeds, say $90 \, \text{km/h}$?

Suppose the speed of light web3g- 6/q fhxxxre infinite. What would happen to the relativistic predictions of length contraction and tixbhgf-qx /3 6xme dilation?

Discuss how our everyday lives would be different if the speed of light were e y;f9yvl72jnonly2n;f yj 9yvle7 $25 \, \text{m/s}$.

Explain how the length contraction and time dilatk6 /8: wtht+ qaegv5-1nam/e gswj.h l( nr;dkion formulas might be used to indicate tjegw5wnhn1ma+ k: shqd ;- av k.8lg/t( /t6rehat c is the limiting speed in the universe.

The drawing at the start of this Chapter shows the street as seen k4cx c0tn5 pz ay7++zeby Mr Tompkins, for whom the speed of ligh4zz+ xtn p+7ek50 aycct 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 trafm3eyx 6hq.9ucud,i4 vel 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 yhf6x,c9 3u4u edq.im not, explain. ----待选择----yesno 

  Can a particle of nonzero 2zf/c 8w .3m,p ih 7.gje:vvk tshi;kcrest mass 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 d- r0s+-vcj nmvn;g;b that a spring has more mass when compre+v s-mdgn0 -n;; vcbjrssed than when relaxed? ----待选择----yesno 

It is not correct to say that "matter can neither be createqli7-uawqiyv ) n k5a )hl*v-/d nor destroyed." What must we say insteadkvaa-nyqwivh-u ) )/*5i 7llq ?

  Is our intuitive notion that velocities simply add, as we did in Section 3–8, c3 sun 5p)c,eulom pl, c)e5u3snupletely wrong? ----待选择----yesno 

  A spaceship passes you at a speed of 0.750c. You measure its length to bepb8:e)d)hx- x 3glryg 28.2 m. How long would it bepe)l d gx)xr8bh-y g3: when at rest? $L_0$ =    m

  A certain type of elementary particle)iw7 vf:k+uf 94bdcz p 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 depend on the fac9j*w 6+m fcf9syz psn(tor $\beta = \frac{1}{\sqrt{1 - v^2/c^2}}$ 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 ligq(g jiedz9(v0ht-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 cdk/ ,yak2a kx +qk+7 t-tg7lcks09hg if its 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-years away. How fasb;9q z8ospae;+ws i:wt would you have to travel so that to you t 9aw sbos+we;zqpi;:8he distance would be only 35 light-years? v =    c

  Suppose you decide to travel to a star 85 light-years away at a speef zo:nwxz0p- 0d that tells you the distance is only 25 light-years. How many years would it take you to make nzpwz: xof00- 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 dve8/ zwry8e-0oqfm r0 je8)tEarth 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 st l;xf,ysfi35h6v mw8xexu t2w : ;.vrdated that starship Enterprise had just returned from a 5-year ,5 ud. rwi3;yl8t: fvxsme vhw2xxf;6 voyage 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 light6 rgz7kt og*,d-years away. How long would it take a spacecraft traveling 0.960c to reach that star from Earth, kr ztg7*d,o 6gas 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"b-vcn-va) s :o spacecraft at a speed of 0.660c. It is measured in yc : ab)vv-sn-oour frame to be 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 travea yhenk,5,s ,)cplv(bl 15 m before it decays? The average lifetime, 5 yvck)lp b(has,n,e, at rest, is $2.6 \times 10^{-8} \, \text{s}$. v =    c

  What is the momentum of a prot0kd3wh)vabx, 3b(j ydon traveling at $v =0.85c$? p =    $ \times 10^{-19} \, \text{kg·m/s}$

  At what speed will an object’s rel-a0ur(*ba zplfaur 7;ativistic mass be twice its rest mass? v =    c

  A particle of rest m j5lx+;1gata ;iz*mth ass $m_0$ travels at a speed $v =0.20c$. At what speed will its momentum be doubled? v =    c

  (a) A particle trave ovh-sx0g7z5il7i mtb69 o v0kls 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 mo2f sw j1 20/ we3rh9shspq8lrimentum of a proton that accelerates
(a) from 0.45c to 0.90c,    %
(b) from 0.90c to 0.98c?   %

  A certain chemical reactiom:i)fs8 hrca)+6o25clql+j cte8pea n 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 apart in the process known ah x9k7kb a6l-y z5+ltos fission in a nuclear reactor, the resulting fragments have a total kinetic energy of about 200 MeV. How much mass was lost in the p x-79h+kz6lotlka5 yb rocess? $\bigtriangleup m$ =    $ \times 10^{-28} \, \text{kg}$

  Calculate the rest energy of an electron in joules an,,a- 0z-e jwvd0aw7a*fje ml jd 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 hy3/nm0zo hzs 0p:lz)a proton in $\text{MeV}/c^2$. $m_0$ =    Mev/$c^2$

  The total annual energy 9vk jd*t4be1utva,8 p8tn9 wqconsumption in the 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 conversionq gdy5g(,3skv 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 kinetic o /-eadkuryw-vv8u0r51 f(sa energy equals its rest energy? v01ks u85afa-y v(rudrw v/oe- =    c

  At what speed will an object's kinetic energy be 25% of its mb;xm6(p6*r 8io saldrest energy? v =    c

  (a) How much work is requiredb()l neiqc ywa8 m1 )-3woqf3m to accelerate a proton from rest up to a speed of 0.99o m3 nyqcebl -(m)8wi1fw3)qa7c? 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 proton trav 7xnk.46)z qtpl9hdvweling $2.60 \times 10^8 \, \text{m/s}$.
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 energy is 750 MeVn+*fx1g7f 8i/* qkjppqo*k sh+f ik qj pnfkp/*g71s*x *o8qh)?    $\times 10^{-19} \, \text{kg·m/s}$

  What is the speed of a prom+hut db98 c1 fqpx)z7ton accelerated by a potential difference of 105 MV? v xzq)7tubh1dcmf9+ 8 p =    c

  What is the speed of an electron whose kinetic energy is 1.4t vs apbl91l5 /l z+udrr7qn600 MeV? v =    c

  What is the speed of an electron just before it hits a televisbd./tqhl s(jhvt9o oxut92q( ;(p 1 hhion screen after being accelerated from rest by the 25,000v(qophh t;t (9o9/hhd .2j1uxqsl ( tb V of the picture tube? v =    c

Two identical particlqj1z,km6ru fg )jkj05pktu+ yg3ms0 8es 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 of a pro52*axqg 4ebez ton ($m_0 =1.67 \times 10^{-27} \, \text{kg}$) whose kinetic energy is exactly half
(a) its total energy, v =    c
(b) its rest energy.v =    c

  What is the speed and thec 5sq:qq bjf(; 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 27e mr mf4o/.8tn,000 kg is accelerated 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 momeikv(n-m j+fb v 5zl5g2ntum 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 nucleusd::swt(ohb + s, $^{241}\text{Am}$, 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 partic8v5w8 ov e6*qw wnxv-rle of nonzero rest mass, and (b) a particle with zero rvx 5ww8w q vnrv-*68eoest mass.

  What magnetic field intensity is needed zif)g +l7wqx+ to keep 998-GeV protons revolving in a circle of radius 1.0 km (at, z+q+iw l7xgf)say, the Fermilab synchrotron)? 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 (wid+ay pk:9:1 ibzgn w0gth respect to the Earth) observes a meteor come from behind and pass her at a speed she measures as 0.50c. How fast is the mend9 g:0iaygzp: kw +b1teor moving with respect to the Earth? u =    c

  Two spaceships leave Earth in opposite directions, e-wk9os4ez. c 02knjbmach with a speed of 0.50c wi29 k4o jkenbz-w.cs0mth respect 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 spaceship leaves the firs l 9wp9qfl*0mtt at a speed of 0.87c with respect to the first. Calculate the sp0mt99l*l fwp qeed 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 s)e:pvk-1s;wk nns t ;npeed of 0.60c. The Enterprise comes to the rescue (Fig. Below), overtaking the aliens while moving dirwepk knstnsv :;n-1);ectly 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 escape pods in opvf w*(lts)h1j posite directions. One travels jl1tf* ws(h) vat 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 B63ut7n*sbe8 wz qa;xee - 6pom passes Earth moving 0.95c relative to Earth in the same direction. How fast is B moving relwab 6sqe eo3- 6tn;7 em8*puxzative to A when it passes A? u' =    c

  The nearest star to Earth is Proxima Centauri, 4.3 light-qw,p3l;l49 4s l1fo/c;fw kge r gfer45 *chfmyears 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 traveling fastet/mb3g ,(h xldr than about 0.1c is called relativistic - i.e., for which the correction using special relativit/l dmx3g(h ,tby 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 speeh2grizak/y* b e6b.; wd $v$ 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 bmb7(4ncscp h 7g67f:ue 0-h9n vreoi ee totally destroyed to run a 100-W lightbulb f49cfu7 hen7(e p:h ver g6-im nc07bosor 1 year? $m_0$ =    $ \times 10^{-8} \, \text{kg}$

  What minimum amount of electromagnetic e9xk/3ae -0 n zb0*pyov uch8uqnergy is needed to produce an electron and a positron together? A positron is a particle wity0nb/k9o08u ch v*e3 xaqup-z h 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 speedj5. vh g 7u8.s,qqfozq of light collides head on with a positive muon traveling at 50% the speed of light. The two muons (eachhq.5,7zo q.8 gqfvujs 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. Assumeszuinbwjb p9et3bo0r3 8*v0 / 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 a9 ebwst 0ub3* 0 z3nr8pibvo/jt rest. KE =    MeV

  The Sun radiates energy at a0 x93aoyse9 *m1qkf p9w8bcxu rate 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 cs ks (o vbrvp;kl i+qx++22woa 7rm+y0harge 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 its c0+umr r n.an 8q: hipjr1e4h)nonstituents, 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. (r0qe:n jn4+m).uin8 hh 1par rThis energy difference is called the total binding energy of the $^4\text{He}$ nucleus.) KE =    MeV

  What is the percentage increase in the (relativisti2rwt)* m0vt7) 9fy*x0zw2xnswm vc khc) mass of a car traveling 110 km/h as compared to at rest? [Hint: use the binomialcmvy2xf ht*sn)tx0 v rw* ) w7kw2mz09 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 mlhg6mwqt v-u)vvb,(- h ke d;6oving toward each ohu66 ,gewvd(hl)t ;v-bqvk - mther. 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 withpeaopb h71 ,t1 momentum $p$ and energy $E$ has a speed given by $v = \frac{pc^2}{E}$.

  The fictional starship Enterprise obtains its power by combining matter alpiojswzmpu5/)81 h5 h b u;e/nd antimatter, achieving complete conversion of mass into energy. oluh)ppzj 8bi /s1;5w5um/e hIf 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 ic 17dyd .bcm+ arp8 iim+h1q4o 0pqcn;s greater than its rest m q1noiydbapmm +h0pc 8rcicd;.q41 +7ass $m_0c^2$ 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 q3 wzag:1q/q il a0r4;ohgsr)(sh n;tpole into a 12.0-m-long barn if he runs fast enough (carrying the pole). Can he do it? Explain in detail. Ho /4qhzqoa 1 0gtla wr)r(nsqg;h:3;i sw 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 oo-( mr wuja781.el gkmh p2u6ucmog*5f oxygen react to form two moles of water, thuwo 7pug-g o.*lcj1(8mm meha 526ruke energy released is 484 kJ. How much does the mass of the 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 particlez cf 1ng:bobbqz8e0 87s are created, traveling in opposite directions. If the speed of each particle 0b zbn eq78b 8z1oc:fgis 0.75c, 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 mebdm n 9m93;4lj/bs tmaasures his ship to be 25 m long. On the ship, he eats his lunch in 2bd9/ sal9;bmnjt43mm 3 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 spee, +vxqu5o6cxg3o z(*a(minfhd of 0.85c away from Earth. You send a laser beam toward the Earth traveling at v xxvuon(3( * 6oqga,mfiz5+h celocity 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 kg. The occupants wou i( mauv nlw/p;)luo:.ld like to travel to a star that is 25 light-years away at a speed of 0.60c. To accelerate, the engine of the spaceship changes mass directly to energy. How much mass will be c). oiaw;:/lvlmu(nu ponverted 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 - (y7jla4kljo*7a f waleft Earth at a speed of 0.99c. What is the spaceship's kinetic energy?fo*a47y- awl a( jlj7k 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 travel to the vicinity of a star 6.0 licjeb-i;qgi + :mdxo4 3ght-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 d:dib ij4+e3 cmox- ;qgone 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 spri)o(35 v. 4sgxhsdpa xtdq7 6oxng whose spring stiffness constant is s)sxpdht dxq x(v64ao.g75o3 $k=48.7 \, \text{N/m}$. 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 maa2du.k sx)7dua *c 4j-hgex x*ss $m_\pi$ 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 $KE_\mu = \frac{(m_\pi - m_\mu)^2 c^2}{2m_\pi}$.