You are in a windowless car in an exceptionally smooth train moving8r 1 :9gs9m1unljqbnr at constant velocity. Is there any physical experiment you can do in the train car to determine whether you are moving? Explus1rjqn9m8n 1l9br :gain. ----待选择----yesno 

You might have had tb u ab 6gac*6q y5kw1+v)y(mlnk-ov(e he experience of being at a red light 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 1(yykak q 6lvbw gm(ac-b5uo)6+*env 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 straigh l1 imq7a7fu1hceg2e,t up (from his poinihlaq7 ue f7,2 gemc11t 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 say lqomb 4ri0-xr7 dwn/ 2that the Sun goes around the Earth? Discuss in view of the first principle of relativity (that there is no best reference frame). Ex mr20i/b7rdox-qln4w plain.

If you were on a spaceship traveling at 0.5c away from a skj; u(r;ru t;e3zwl5xtar, at what speed would the starlighx;ru(we j l3;ru;ztk5t pass you?

The time dilation effect is sometimes expressed as “moving clocks run slowly.” Awf rmf6u*60n dctually, this effect has nothing to do with motion affecting the functioning of cldn6 r6wf*u0fmocks. What then does it deal with?

Does time dilation mean that time actually passey06hpvjktj-/ t;4pv 7p j :iaes more slowly in moving reference frames orj-6/y :t0vhpektppi47v a j j; that it only seems to pass more slowly?

A young-looking woman astronaut has just arrived ho kwl3c4 p (4ipwab+bx*me from a long trip. She rushes up to an old gray-haired man and in the ensuing conversation referpb3a(wk4c ixlb+w p*4s 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 change icefb.(sg9ue ob6 .d 4pn your heartbeat? Would your mass, height, or waistline obsef .b4p. g(c6 9eudchange? What would observers on Earth using telescopes say about you?

Do time dilation and length contraction occur at ordinaryw1vs 4j emm-:y speeds, say $90 \, \text{km/h}$?

Suppose the speed of light were infinite. Whoj6 vtr96if7a1 h1gd8: becsuat would happen to the relativistic predictions of length contrs1 fg cv 9:ed6itr8o 61hu7bajaction and time dilation?

Discuss how our everyday lives would be different if the speed of light were onl//j ; zzaay/ +ci9hetjy zc;j/e tz+/aajy/i9h $25 \, \text{m/s}$.

Explain how the length contr x+1 ii;y1 qzgsq*1h+r pjwqf2action and time dilation formulas might be used to inqi1 jx gzw+1+f 2 r*iq1qyp;shdicate that c is the limiting speed in the universe.

The drawing at the start of this Chapter shows the street as seen by Mr Towhxay9x-)j5 t t 2d:campkins, for xt)w cj2aay:hdx-9t5whom the speed of 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 trave ) py(h+1lqgio;md1xql at speeds less than c. Does this put an upper limit on the momentum of an electron? If so, what is xq(+ih)pol1;qdg 1my this upper limit? If not, explain. ----待选择----yesno 

  Can a particle of nonzero rest mass alyzk;rpfg53mn08h;6)b a ama ih0 g n/ttain 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 spring has more mass wa 6d;vqlty8y (hen compressed than whe;(t8y qa6l vdyn relaxed? ----待选择----yesno 

It is not correct to say that "matter can neither be creata zm e ie24*fcmf+:ll-ed nor destroyed." What must we say insteadm2-*cmaz 4:fiel e+lf?

  Is our intuitive notion that velocities simply add, as we did in Section 3–fs9ty 8at : okr/d*p;p:9zz ym8, completzak;f9y*/8m od9prp: zt s:tyely wrong? ----待选择----yesno 

  A spaceship passes you at a speed of 0.750c. Youv+q0b zbg hw+b0u*u 9w measure its length to be 28.2 m. How long would it be when at res+0w + *zwbh9 vquubgb0t? $L_0$ =    m

  A certain type of elrs+.(g/ r9 0yp qighrhf2f dh2tj3 s5wementary particle 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 0t8 g topeyz3,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 lw,k hz2t/ (8de wv8ktedoxr69ight-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 gi)h-78 uqy k+wudgh(ks9 8kq /+rlae pion 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 awaydwf cu(w*cn0k s/x86zayk0m ej*ic6.. How fast would you have to travel so that ce/kyfdj8* *w.z6i6 a0 m0ucnkws(xcto you the distance would be only 35 light-years? v =    c

  Suppose you decide to trn;ge p0pf9. lkavel to a star 85 light-years away at a speed that tells you the distance is only 25 lielnkgp 9p ;f.0ght-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 the Earth is;n34 (to fv: ungjjgzo8fw o)* $11.2 \times 10^3 \, \text{m/s}$. 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 just returned from a 5qvvhn98 lu,h;e9mo y5-year voyage while traveling a5nuvv9me,o l 8h9hyq;t 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 take a spaum:k-wm(yju c4 m 18zucecraft traveling 0.960c to rek 1(m-8zu4: wmjmuuycach that star 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.vv4grxb6r a( her "Ferrari" spacecraft at a speed of 0.660c. It is measured in your frame to be 4.80 mb x(ra4.6g vvr 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 trav4yn3 ;cr ozhz 18z/;i. letuvtel 15 m before it decays? The average lifetime, at rest, is z z; 1tcy8 ;uinl./rz34hveot$2.6 \times 10^{-8} \, \text{s}$. v =    c

  What is the momentum of a p6.m tt0-d:idp rovy 5iroton traveling at $v =0.85c$? p =    $ \times 10^{-19} \, \text{kg·m/s}$

  At what speed will an object’s relativistic mmy /y6 jrg v651nbtb2fl1a 0rsass be twice its rest mass? v =    c

  A particle of rest mass7vxfjse xa/3 8yba8qf,h+tq- $m_0$ travels at a speed $v =0.20c$. At what speed will its momentum be doubled? v =    c

  (a) A particle traveloxo:fb2i yfi;0-y 9v ms 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 ibr:ddt yc e(r1( i5)sdn momentum of a proton that accelerates
(a) from 0.45c to 0.90c,    %
(b) from 0.90c to 0.98c?   %

  A certain chemical re8p,.v+g hzfotboq6- uaction 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 breakmxcl ;,2w4spl1e6( bru xr27ny7 lw dys apart in the process known as fission in a nuclear reactorlwu;4(pby72mlwe cr 61xn,l s7rd2 x y, 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 electron in joules andr5tzj6.6h a.jwtx ax0 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 pr28 rlf yzh3v4doton in $\text{MeV}/c^2$. $m_0$ =    Mev/$c^2$

  The total annual energy consumption in the Unlx/en)pda u5 ; ,m1nwrited 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 gram of mass?6o.) ie.h+ lztvh -qfe    $ \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 enek4 eb/p u*kx2 gq .:szaty2/olrgy equals its rest energy? /q 2g k2ea zy:bp*o/ st4xu.lkv =    c

  At what speed will an object's kinetic energy be 25% of its r0 a: apb(;jvhtest energy? v =    c

  (a) How much work is required to accelerate a proton from rest up to ao ;8tce/4csr7a.hmpt speed of 0.997c? W oct.h84t/remcsp 7a; =    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 travelingx 1t8 7p9zl +omj4lqal $2.60 \times 10^8 \, \text{m/s}$.
KE =    $ \times 10^{-10} \, \text{J}$
p =    $ \times 10^{-18} \, \text{kg·m/s}$

  What is the momentum of a 750-Mv5c h vc 45ly-7h)bfnpeV proton (that is, its kinetic energy is 750 MeV)?yblv45p h7v)cn-hc 5f    $\times 10^{-19} \, \text{kg·m/s}$

  What is the speed of a proton accelerated bf9nuq0/ 2 uefp oik/y(y a potential difference of 105 MV? v upfq(/kuof9e 02i/ ny=    c

  What is the speed of an electron whose kinetic energy is 1.00 1 1dfk(rb: kg* 1skojlMeV? v =    c

  What is the speed of an electron just before it hits a television screen after b9g0+gr a20(qe(at e(sic djad;r0 mlmeing accelerated from rest by the 25,000 V of+r ag00qe2;(gitc em(ad jd (0 smlra9 the picture tube? v =    c

Two identical partic 7zmdmx g-g12g:wj3nales 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 oor62qxb(xu*o c. sk6cf 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 and the momentum of an elec;9h j8u6nlbi/jek bs(tron ($m=9.11 \times 10^{-31} \, \text{kg}$) whose kinetic energy equals its rest energy?
v =    c
p =    $ \times 10^{-22} \, \text{kg·m/s}$

  Suppose a spacecraft of mass 27,000ekbnuap8xi5;8r3 18 sx z6ix n 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 andyf zt z2;qm2m; 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 nucleu z-apxa0vhvvj260l b4 ftwj- *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 kineticvtsxhlo3jn l j4,v ;3p4yq:/n energy versus momentum for (a) a particle of nonzero rest mass, and (b) a particle with zero rest m tj :vjhn;ys4 pn3l l4,xq3ov/ass.

  What magnetic field intensity is needed to keep 998-GeV protonskewu v7 )23xwd revolving in a circle of radius 1.0 km (at, say, the Ferw 2vk7wex)3u dmilab 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 (with respect to the 2uovfj:9z 5ybfyx/jn94atm2 Earth) observes a meteor come from behind and pass her at a speed she meambyax4 fujj/zy9vf2n5o:2t 9sures as 0.50c. How fast is the meteor moving with respect to the Earth? u =    c

  Two spaceships leave Earth f.awny n; 40kkin opposite directions, each with a speed of 0.50c with respe4. wk 0y;annfkct 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 tv,dpg0p-m*o d raveling at 0.71c. A second spaceship leaves the first at a speed of 0.87c with respect to the first. Calculate the speed of the second ship with rem-v0 p pdd,*gospect 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 speednso c1t( :c+nn of 0.60c. The Enterprise comes to the rescue (Fig. Below), overtaking the aliens while moving directly towa(t1nc:+s onn crd 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 tmaj8 7v,e (o :8jkkq-pze9cahwo escape pods in opposite directions. One travels at a 7(k 9qahaepozk8e, m8vj:c-j 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. Aoc vnhm 3sxl *t34.,het the same time, rocket B passes Earth moving 0.95c relative to Earth in the same direction. How fast is B moving relative to A when it passesxnol3hvhm4* c,3 s e.t A? u' =    c

  The nearest star to Earth is Proxima Centaur- (ix-zr21 pf;le6u qoy7pz)fkdup3 gi, 4.3 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, auw-) 9hhw:r *xjrjxeb( .ob h0nything traveling faster than about 0.1c is called relativistic - i.e., for which the correction using special wh-ruhw.*ej hr 0 jb b9:xxo)(relativity 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 speedgq9y t52rdk6 w $v$ 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 rub8vz+cfd y9jm+v* 76.lb srs 7rn5u bun a 100-W lightbulb for 1 year?drsnuvb7z 7rm jub+. lyc9*8b56 v+fs $m_0$ =    $ \times 10^{-8} \, \text{kg}$

  What minimum amount of electromagnetic energy is ne15s 8nkgmoj 203s+wy v v*pj* ;ad+yzuxyeh(jeded to produce an electron 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 charge is conserved(js; +v*o2h1p kjyjn zusd083y+xg mw5*ve ya 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 pm5h3dmp9hm i0i9c 3,i0 jgeye speed of light collides head on with a positive m,em59di0h0g3yh3 m 9pij ipcm uon traveling at 50% the speed 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 decay into a proton, an electron, and a neutrx -6k;hjt lph 6jdy7u 4t, ,4itbpq:buino. 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. Ku,;t4dqthy 667tp jh,i-jbb u k:x l4pE =    MeV

  The Sun radiates energy at a rate d,c b)ft*4x j13uue6ofnwhf 8of 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 havq5w,go j/ ;vtg)ywohc;1 ev u3e 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 its cd-w1f5h o7 rw6xhi2lbonstituents, two protons and two neutrons? The rest masses of a proton (including an electron), a neutron, and helium are, re6i2w orhl fd-1x75w bhspectively, 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 k mgjl3(2h,v,u.iy e2niyk:ein the (relativistic) mass of a car traveling 110 km/h as ck, 2gye(:ml3 je i2.ynkiuvh ,ompared 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 lz,vd 1+im4 jhbaboratory, are moving toward each other. Determzi jm+ 4,1hdvbine
(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 parti mf.;id;w efh- rv22avcle with momentum $p$ and energy $E$ has a speed given by $v = \frac{pc^2}{E}$.

  The fictional starship Enterprise obtains its power by ccwkafw(c 5-/zy *2kl yombining matter and antimatter, achieving complete conveac5/zfww ky k(*l2 -cyrsion 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 m ysack;d7 h9+its rest mass9 +acd7myh ;ks $m_0c^2$ 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:w,ytu x5t7c2g+szdg believes that he can fit a 15.0-m-long pole into a 12.0-m-lo:+t w stdgxz,gc7y5u 2ng 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 molelo 3nvn6;a)ec of oxygen react to form two moles of water, the energy re;ecv6l n no)a3leased 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 particles are ms;e.)fi,gpmqs. 51h) +dqscp r.nrecreated, traveling in opposite directions. If the speed of each particle is 0.75c, relative to the lacr + diq1m)hmp .)e5qpss.nge;,sf .rboratory frame of reference, what is one particle's speed relative to the other particle? u =    c

  An astronaut on a spaceship traveling at 0. adp;qakv60g k/ri/w575c relative to Earth measures his ship to be 25 m long. On the ship, he eats his lunch6k5;/ /iva w0daqr gpk 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 ash4/ ;fsn xc:kk aqt,+way from Earth. You send a laser beam toward the Earth traveling at velocity c relative to you. What do octq+; n4s k ak,hxfs:/bservers on the Earth measure for the speed of the laser beam?

  A spaceship and its occupants have a total mass of 150,000 kg zu9oqiov ;d-5. The occupants would like to travel to a star that is 25 light-years away at a speed of 0.60c. To accelerate, the engine of theqo d5zv o9i;-u 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 speeth( ; vxfagr;j*crj;h5rd tz,5p p(g* d of 0.99c. What is the spaceship's kinetic energy? Compare with the total U.S.rxa ; hj p,z(g hf*g;r;t*5jt5vpd (rc 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 light-yg5w*(pe ml/qu pb q fq5)ler;*ears 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 qb*m q;l5*r/ upl 5g(ew fep)qtrip? u =    c

  A 1.68-kg mass oscillates ow.av.wqb)az 1 n the end of a spring whose spring stiffness constant awz). w1vb .aqis $k=48.7 \, \text{N/m}$. 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 manhim0 drthok i).ef*xe w3 4cnn7)-5vss $m_\pi$ 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 $KE_\mu = \frac{(m_\pi - m_\mu)^2 c^2}{2m_\pi}$.