You are in a windowless car in an exceptionally smooth train movif-.xpsz( uqs3 fn(b8cng at constant velocity. Is there any physical experiment you can do in the train car to determine whether youq-( n zs3bus(.ffcp8x are moving? Explain. ----待选择----yesno 

You might have had the experience of being at a red light wheu5u jc91qnt)2 ajec-wn, 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 rolling backward. What does this say about absole9)a 1 jjuw-ntcq2 u5cute and relative motion?

A worker stands on top of a moving railroad car, and throws a heavy bal. gw*yb8dd4h593 sn(u or lkwql straight up (from his p8k*n9 q4gshwr 3buod .l w5(dyoint 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 bo57sbw8c18 n2iqzqwalid to say that the Sun goes around the Earth? Discuss in view of the first principle of relativity (that there is no best re5 bqozqb8 w1287swicnference frame). Explain.

If you were on a spaceship traveling at 0.5c away from a star, at what speed wour 4++( 0 iyrmyxxmtgd6ld thm0g+x y(6 yt dr+mixr4e starlight pass you?

The time dilation effect is sometimes expressed as “moving cllyt6v4e 0k)p tocks run slowly.” Actually, this effect has nothing to do with motiont4pek l)6yt0 v affecting the functioning of clocks. What then does it deal with?

Does time dilation mean that tild z)2fq7 lmttq 4))hkme actually passes more slowly in moving reference frames or that it only se2 l tq7fdl)qt ))kh4zmems to pass more slowly?

A young-looking woman astronaut has jusoi k0z2l7 sbn6t arrived home from a long trip. She rushes up to an old gray-hair7onks z6 02blied man and in the ensuing conversation refers to him as her son. How might this be possible?

If you were traveling away from Earth at 7qd+df) v yx+ar.3cb pspeed 0.5c, would you notice a change in your heartbeat? Would your mass, height, or waistline change? W d q)c +fv.7b3a+yrxdphat would observers on Earth using telescopes say about you?

Do time dilation and length contraction occur at ordi bc11 i1ydwv6cnary speeds, say $90 \, \text{km/h}$?

Suppose the speed of light were infinite. What would happen to the relativisticur23rigk p((w(-vw wz predi3zgv (krw-(ipwr(2 uwctions of length contraction and time dilation?

Discuss how our everyday lives woun: i+(1oipjn hz/z:12p3r ru fbt3keeld be different if the speed of light were onlyzfhjn/( pu 1 t zek3no3br2e:pr1+ii: $25 \, \text{m/s}$.

Explain how the length contraction and time dilationmb7u29 4 pekhz/)fj ke formulas might be used to indicate that c is the limiting speed kj7/b 2fmu9ehkp4z) ein the universe.

The drawing at the start of this Chapter shows the street as si,1prli *: sweeen by Mr Tompkinsl:piie,*1r s w, for whom 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 travel at speeds less than c. Doesqqmv62h;)yh* meich6 wz4 jl/ this put an upper limit on thelmj h*m4 qqe6h)6/c izvh2wy; momentum of an electron? If so, what is this upper limit? If not, explain. ----待选择----yesno 

  Can a particle of nonzero rest mass attain the ik5.oae48ay lab pa-* 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 sprine.w/p ,w ehkfcud2e93g has more mass when compressed than when relaxeue 32h. pw9fkwe,ec/dd? ----待选择----yesno 

It is not correct to say that "matter can neither be created no83n tp+g ma pw(/i;lunr destroyed." What must we say inspg+ ;(8p u3niwl /nmtatead?

  Is our intuitive notion that velocities sw:nshqqvpyyd91.0zhf-5+q-. q do vg imply add, as we did in Section 3–8, completel.qdq:0.hf q o h1ygsdv+vp9n qwz5- y-y wrong? ----待选择----yesno 

  A spaceship passes you at a speed of 0.750c. You measure ib g4x6a)4da cwsgxfaxo2* iff( )8p+jts length to be 28.2 m. How long would it be when at restg*4fbj(+ )x68xoff 2wag 4i)ax pscda ? $L_0$ =    m

  A certain type of elementary particle 2 hki1s1s4eal 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 o/xkvoog z6k) oyi p/ f xws(9wss-.-c3n 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 x93 yqhq95t;fiinnr6 h p/m8g speed of $2.50 \times 10^8 \, \text{m/s}$, what would you measure this distance to be? L =    ly

  What is the speed of a pion if its average lifetime is measured to be qdjjah k :kjgq:yf54h6z. 2qfd *4 6um$4.10 \times 10^{-8} \, \text{s}$? 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 fast would you hmnr2r hw;h/wz,9h y8eave to travel so that to you the distance would be only 35 light-ye 8yw2hm; zr,w9rhn /hears? v =    c

  Suppose you decide to travel to azz2 6ju( k ty 8eh5f(b*ye6sex star 85 light-years away at a speed that tells you the distance i8zf(e6 * 6x yu2ebzjytk5 hs(es 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 the Earth is 5k-2ex 6yzdlb$11.2 \times 10^3 \, \text{m/s}$. 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 starshipd* 2ou ime(ii9.d8s;r en3nag Enterprise had just returned from a 5-yeuom*g(edeni ri23 n8.a9si;dar 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 light-years away. How ajl;)uogbew ;m*dpl/5l g.;+wjy o-f long would it take a spacecraft traveling 0.960c to reach thlp/ujgledoa;ww;mgybj+f o;5l*. -) at 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 her "Ferrari" spaw is-ie8r/a lah; h);d7q.z gfcecraft at a speed of 0.660c. It is measured in your f.h i/-glid 7) ha8zf rq;wes;arame 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 travel 15 m before it decays? The 9(yoqzwf, a7b average lifetime, at rest,7abq,wo zy f9( is $2.6 \times 10^{-8} \, \text{s}$. v =    c

  What is the momentum of a protou.8ukbi bt+2 bq5 fbn3n traveling at $v =0.85c$? p =    $ \times 10^{-19} \, \text{kg·m/s}$

  At what speed will ak6+ u. nuyk bpg8 2v0ov,a0e)b9g slqvn object’s relativistic mass be twice its rest mass? v =    c

  A particle of rest masx;hr/s*/ irt0 pkhlm*0x smf(s $m_0$ travels at a speed $v =0.20c$. At what speed will its momentum be doubled? v =    c

  (a) A particle travels ath l81nz5 yxis e 4k-1pzb5qs-x $v =0.10c$. 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 ya+ cjl9t wc wu.5s0r*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 v 3e7lq/y3xbp$4.82 \times 10^4 \, \text{J}$ 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 k k9qfmxc ,ycbd9m/i7 -nown as fission in a nuclear reactor, the resulting fragments have a total kinetic energy of amb 9 yfqxk/c 7md-9,icbout 200 MeV. How much mass was lost in the process? $\bigtriangleup m$ =    $ \times 10^{-28} \, \text{kg}$

  Calculate the rest energy of an g) o(chc:k)zaelectron 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 myj6a i;(l3juy ass of a proton in $\text{MeV}/c^2$. $m_0$ =    Mev/$c^2$

  The total annual ener vq2b +x,ou1nll/b jt8gy consumption 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 bl82s0wm( k w vryz1f-ce obtained from conversion 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 particlve7oki9opsi 6( o:8: dej:inae when its kinetic energy equals its rest energy? v =ie:o n7 8od6pjis:vi(e9:a o k    c

  At what speed will an object's kinetic energy be 2uf( ibulv93j)oa c9(j 5% of its rest energy? v =    c

  (a) How much work is required to accelerate a proton from rest up t 3/vw(i) jhh*eoism.jo a speed of 0.997c.sji*j )/ vwehi(om h3? W =    GeV
(b) What would be the momentum of this proton?p =    $ \times 10^{-18} \, \text{kg·m/s}$

  Calculate the kinetic en1oe8/,h,i.inv y loq mergy and momentum of a proton traveling $2.60 \times 10^8 \, \text{m/s}$.
KE =    $ \times 10^{-10} \, \text{J}$
p =    $ \times 10^{-18} \, \text{kg·m/s}$

  What is the momentum of a 750-MeV proton (ts3h /r4nl9g8ubw xyk8hat is, its kinetic energy is 750 MeV)?/88u9rbgn3hl4ywk sx    $\times 10^{-19} \, \text{kg·m/s}$

  What is the speed ofi7hv+u+hgla:* y6tj)s kp 6pr a proton accelerated by a potential difference of 105 MV? v = v+ry hi jt)*l :76hpkgup 6s+a   c

  What is the speed of an electron whose kinetic energy ) njf4njw)w0dmfxz.8is 1.00 MeV? v =    c

  What is the speed of an electron just before it hits a television screen after by5v;tv; f+ ypeeing accelerated from rest by the 25,000 V of the picture +py5;evtv; yftube? v =    c

Two identical particles a+4n h9*o)svt/zhf h oof 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 +d4:oq4ekoa xa 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 m 0c(8lsfqv u ;7jylgn3omentum 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 accele i5q s1s42edextkp,e(lsq6 )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 momentum of hp c.srt4f)9 aa proton ($m_0 =1.67 \times 10^{-27} \, \text{kg}$) traveling $7.35 \times 10^7 \, \text{m/s}$. By what percentages would your calculations have been in error if you had used classical formulas?
KE =    $ \text{MeV} \, $ with an error of    %
p =    $ \times 10^{-19} \, \text{kg·m/s}$ with an error of    %

  The americium nucleus sk7agsl* hh1 +j)fx (a2c/hit, $^{241}\text{Am}$, decays to a neptunium nucleus, $^{237}\text{Np}$, by emitting an alpha particle of mass 4.00260 u and kinetic energy 5.5 MeV. Estimate the mass of the neptunium nucleus, ignoring its recoil, given that the americium mass is 241.05682 u. $m_{Np}$ =    u

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

Make a graph of the kinetic energy versus momentum for (a) a particle of non+k95 cu/e3i0n xfr sdnzero rest mass, and (b) a desif9k+0/x53nu r ncparticle with zero rest mass.

  What magnetic field intensx)m:v8r.y5ffgt kfja ++is ) bity is needed to keep 998-GeV protons revolving in a circle of radius 1.0 km (.jx8+a rfkbt)if):5v fgsm+yat, 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 (with respect to y q gs8.ss0(bkthe Earth) observes a meteor come from behis0ksqsgy. 8b( nd and pass 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 with a speed oyi ptb )sp0ra)0g-qzu )oh,27ak.m fkf 0.50c with respect to Earth,)iyashzb-ka2.pmor0 up g 7 qt)f)k0.
(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 leaver )o.4fdjf uk;s the first at a speed of 0.87c with respect to the first. Calculate the speed of the second ship with r.u f krodf4);jespect 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 vess167 sq1 tu*7 htqbhzcxsv)fi;el approach at a speed of 0.60c. The Enterprise comes to the rescue (Fig. Below), overtaking the aliens while moving directly toward Earth at7*1xq;tvqf1b7t)z6hc hi uss 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 sen//q /mz0op;br;zn sx fds out two escape pods in opposite directions. One travels ato bp x;;z fs0rzq/m//n 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, ro ale;nm39xot3hub 9 ,n/n)oggcket B passes Earth moving 0.95c relative to Earth in the same direction.n mnhun/ eob axtg9 ;33)ol,9g How fast is B moving relative to A when it passes A? u' =    c

  The nearest star to Earth is Proxima Centauri, 4.3 light-+-g9 znv(bmf v0 oj(y d1pspn0years 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, anythino gf7f5g rqbqn1v lmz.v-jj6oy* o85/ g traveling faster than about 0.1c is called relativistic - i.e., for which the correction using special y/jq5g 8fz-oj57 n6qbov f1lrv * gmo.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 spee(pah 2yuxg*j 6d $v$ 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 b9 nk+c1t nzj9zgq.p1 have to be totally destroyed to run a 100-W lightbulb for 1cjkn 1t1gn+ qp9zbz. 9 year? $m_0$ =    $ \times 10^{-8} \, \text{kg}$

  What minimum amount of electromagnetic energy is needed to produce an electron mnx7ihroj9 j0qp a2gg-l2o) ,and a positron together? A positpjh072q2)x-no,mg a l9gj or iron is a particle 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 of o9 ocgj drkll.jw+l c.+32.dklight collides head on with a positiol+3. 2dld+9rg.lkcjc.kw jo ve muon 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 neutrino. Assume ;z 0zq(pwkf2-vt 2 ylwthe 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 am-lvfw y20p2 kq;(wzztong the three particles when a neutron decays at rest. KE =    MeV

  The Sun radiates energy 3ku sn:kz* z,em;6kve at a 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 negatisutil x89m b1-ve 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 b*xlcnu m0 :ycx5 93 8xcqagf3kreak a helium nucleus into its constituents, two protons and two neutrons? The rescgcu fyx 083ma 3k 9lx:n*cq5xt 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 called the total binding energy of the $^4\text{He}$ nucleus.) KE =    MeV

  What is the percentage increase in the (relativistic) mass of a car trave l ,*+f4n4lu r5cgwyweling 110 km/h as compared to at r+nuc 4wglfyl4w*5e ,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 f8jh4 zilue+1the laboratory, are moving toward j 48le1+fz iuheach other. 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 wic p a,1oymi*b., c.3vaxfc5xulzh86fth momentum $p$ and energy $E$ has a speed given by $v = \frac{pc^2}{E}$.

  The fictional starship Ene dj.c1z 3(2l8euwyq ndao.4 kterprise obtains its power by combining matter and antimatter, achieving complete conversion of mass into energy. If the mass c.1n4 3zud.(wq2a djkoy8e leof 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 thatx u-5)o+d j(d2 v)z lyb+zssfv its kinetic energy is greater than its rest m+dd 5 +jsoluv2)fz)y (bs- zvxass $m_0c^2$ 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 phyjv*cj ok0.i k1sics believes that he can fit a 15.0-m-long pole into a 12.0 10*kcj. ojikv-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 running the barn looks even shorter to him than 12.0 m? ----待选择----possiblenot possible 

  When two moles of hydrogen anykf0 eii8j(xi h9;.k9lg5- 3z ayu qwod one mole of oxygen react to form two moles of water8q zko ijyg3w9xkh(le;f5.i0 9iyu -a, the 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 particles are created, traveling in ok(n3; fompug8 i mgx5e-c:j7 epposite directions. If the speed of each particle is 0.75c, relative to jo(k-enumcme 5 ;:figp87gx3the 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 to0qx: xjc 5e rte;wysww dy(xw(s4;m*/ Earth measures his ship to be 25 m long. On thw(dr e4wyx*y m/ew ;5x 0qssjw;(t:cxe 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 spaceship at a speed of ojoq uqj38*hq)4 6xe x*nnff+0.85c away from Earth. You send a laser beam toward the Earth traveling at velocity c relative to you. What do ob 3 ffx6oqxj*q n*n e+q4ju8ho)servers on the Earth measure for the speed of the laser beam?

  A spaceship and its occupants have a total mass of 150,000 /lt8r svi68 v2ultuj6jm kz::kg. 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 the spaceship changes mass directly to energy. How much masktl m:r 6ju/ivl6v:8zjst8u2s 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 0.99c. What i).4g,sle0u iue s2vsks the spaceship's kinetic energy? Compare wit2s )ei0sv, uue. kslg4h 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 light-years)3 otilt5pw bq-4b b(e 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()4 e5otqt3bpwi l-b b the speed necessary for this trip? u =    c

  A 1.68-kg mass oscillates on the end of a spring whose spring stif/upm dnhmyxb y ,;y 8h65wy7no5/ ;nxafness constant is,6;y/uw m;dyyaxh p5/ x n87 nbyo5nmh $k=48.7 \, \text{N/m}$. 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 mas+,m,u qc3q zwf54ujqnc1q13yp 7cx ics $m_\pi$ 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 $KE_\mu = \frac{(m_\pi - m_\mu)^2 c^2}{2m_\pi}$.