You are in a windowlesnp88x 73wax* uzag qq9k)ayg;d:sc g7s car in an exceptionally smooth train moving at constant veloci ggkw;x98y3qd a8a ncas)xpq7*z7:gu ty. 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 be t8lu8g 4p.otiing 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 yo8 o glptui.4t8u are rolling backward. What does this say about absolute and relative motion?

A worker stands on top of a moving railroad car, and m3w4xr ymy j1 :qrw3u4throws a heavy ball straight up wm4m:qyu4r1rxj3w 3 y(from his point of view). Ignoring air resistance, will the ball land on the car or behind it?

Does the Earth really go around the Sun? Ok8p 8fukq(/omr is it also valid to say that the Sun goes around the Earth? Discuss in view of the first principle of relativity (that there is no best re /8qkpomk8f( uference frame). Explain.

If you were on a spaceship traveling at 0.5c away from a star, at what s31hibkj kx;7fat6yc dy65:fr+z + ss gpeed wou:g k6s5ya+bc jz3ih6dkyrf 7+f st;x1ld the starlight pass you?

The time dilation effect is sometimes expressed as “moving clocks run sq- 4i3rtk.xuklowly.” Actually, this effect has nothing to do with motion affecting the functio3tqrxk iu.4k- ning of clocks. What then does it deal with?

Does time dilation mean that tim18pz71ch5 e nxgyg6hxe actually passes more slowly in moving reference fraex cz pgy17 15hx8gnh6mes or that it only seems to pass more slowly?

A young-looking woman astronaut has jqo3d0q2 clq b6anoi.n,6(rxhust arrived home from a long trip. She rushes up to an old gray-haired man and in the ensuing conversatioqnq.cl6( h 0bx,6 oio3nrdq2an refers to him as her son. How might this be possible?

If you were traveling away from Eavnwet tm:1zjb.- : l6lrth at speed 0.5c, would you notice a change in your heartbeat? Would your mass, hzt .lj6t::ev1nlmb w -eight, or waistline change? What would observers on Earth using telescopes say about you?

Do time dilation and le-l,x ,ql 5 nmkyp(j2nlngth contraction occur at ordinary speeds, say $90 \, \text{km/h}$?

Suppose the speed of light were indb -srk0)b(:inp4vb km .tmu-finite. What would happen to the relativistic predic :4(msbtuiv k-dmp0b) r k-.nbtions of length contraction and time dilation?

Discuss how our everyday ctdb(n.i2)y0g 2 z2/, 8ovvip yyi zhalives would be different if the speed of light were onl(yb.v 2)dpc2/o ,z n02a giyvhztii 8yy $25 \, \text{m/s}$.

Explain how the length contraction and timel.6m .u1cpd)thhp ) rx dilation formulas might be used to indicate that c is the limiting speed id )cru6 x) lp1.hhmtp.n the universe.

The drawing at the start of this Chapter shows the street asj ff1f)k t /99p/)4jfz4/l ahkmlkrgx seen by Mr Tompkins, for whom the speed of ligf k4kkf9)1) rz ga9mjxf/jp4/ l ltfh/ht is $c=20 \, \text{mi/h}$. What does Mr Tompkins look like to the people standing on the street? Explain.

  An electron is limited to travel at speeds less than c. Does t pwc+.t)-j osshis put an upper limit on the momentum of an electron? If so, what is this upper limit? If npc+.js ws o)-tot, explain. ----待选择----yesno 

  Can a particle of nonzero .dahp dd ke-85rest 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 that a spring has more mass wheg9 q):7gfbkhen compr) bg 79qh:kgfeessed than when relaxed? ----待选择----yesno 

It is not correct to say that "mat) -nsth 8ubjtx,zjg+ /ter can neither be created nor destroyed." What must we sa gzt+x)tjsh- jb8/ ,uny instead?

  Is our intuitive notion that velocities simply add, asnv oo*k ,* ub9skc(y4g we did in Section 3–8, comply(con9v*s* ogb kk4, uetely wrong? ----待选择----yesno 

  A spaceship passes you at a speed of 0.750c. You pchh/;kh+,jie 2tu, w measure its length to be 28.2 m. How long would it hkt;, /,c+uiejh2hp wbe when at rest? $L_0$ =    m

  A certain type of elementary pa opo :)jsuz36u zsi)q.rticle 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 facto4woh 6 u11lltw7+e. qg iuiv3lr $\beta = \frac{1}{\sqrt{1 - v^2/c^2}}$ 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 zijdju q5t:-6 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 r p8vko* 6;81u abcyurbe $4.10 \times 10^{-8} \, \text{s}$? 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 awb6)890xs; xrez d qownay. How fast would you have to travel so tox;80 rdnqb9w6se z)xhat to you the distance would be only 35 light-years? v =    c

  Suppose you decide to travel to a star 85 light-years a e c43+zfg7bvgway at a speed that tells ybge4 c3zvgf 7+ou the distance is only 25 light-years. How many years would it take you to make the trip? t =    y

  At what speed $v$ will the length of a 1.00-m stick look 10.0% shorter (90.0 cm)? v =    c

  Escape velocity from the Eartha57oidi 0im5 l0f:szs is $11.2 \times 10^3 \, \text{m/s}$. What would be the percent decrease in length of a 95.2-m-long spacecraft traveling at that speed? L =    $ \times 10^{-8}\%$

  At what speed $v$ do the relativistic formulas for (a) length and (b) time intervals differ from classical values by 1.00%? (This is a reasonable way to estimate when to do relativistic calculations rather than classical.) v =    c

  Suppose a news report stated that starship Enterpr;bmeh33-tcca0 xae7 q z2v r)mise had just returned from a 5-year voyage while traveling at 0ece;mvr0)tb7h a233 cqzm ax -.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-yeat:sjyo4 1u6vg5y v.63plaex o rs away. How long would it take a spacecraft travvo:s. oyx6a egtl5jv134yu6p eling 0.960c to reach 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 her "Fer/es6az52f ypu coeo:u/mbj* pc:bd2 jf9 +b, lrari" spacecraft at a speed of 0.660c. It is measured in your frame to be 4.80 m long and 1.25 m hybp:z9 dpf/m5e u *o fb j+lcsjb:c/,22o6ue aigh.
(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 qv0n r(7(mml vto travel 15 m before it decays? The average lifetime, at r(ml v q(0mvrn7est, is $2.6 \times 10^{-8} \, \text{s}$. v =    c

  What is the momentum of a proto:myxwlgg , ax5pg 2x4e:qdq34a got63 n traveling at $v =0.85c$? p =    $ \times 10^{-19} \, \text{kg·m/s}$

  At what speed will an object’-o707pntmu,u;dscws 80 xl xp s relativistic mass be twice its rest mass? v =    c

  A particle of rest massxctz y4) uz hwe-1q0w5 $m_0$ travels at a speed $v =0.20c$. At what speed will its momentum be doubled? v =    c

  (a) A particle travels r(j wqo6,my4gr4. p di/vwnc1 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 momentum ;4ujrzrjw /8pof a proton that accelerates
(a) from 0.45c to 0.90c,    %
(b) from 0.90c to 0.98c?   %

  A certain chemical reaction 7e*y/f3ebkv-6mg yin 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 break1u pcl3fm,7d*j7 aadl s apart in the process known as fission in a nuclear reactor, the resulting fragments have a total kinetic energy of about 200 MeV. How much mass was lost in t7l3lj17 *cf ,p daaumdhe process? $\bigtriangleup m$ =    $ \times 10^{-28} \, \text{kg}$

  Calculate the rest energy of an ele-e agf,o s3-tf5lau f+( 6ulxv8q 8plectron 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 mass of a;dc:ojfm-cns unxs5) un/ 4 nrfn6 x8. proton in $\text{MeV}/c^2$. $m_0$ =    Mev/$c^2$

  The total annual energy consumption in the United States is abouta.ufbf-3,bko+by 2k v $10^{19} \, \text{J}$. How much mass would have to be converted to energy to fuel this need?    kg

  How much energy can be z5d ub2,w*e:evtxe 7 o1*hrkxobtained 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 ak/ bm8b tyoe;4 particle when its kinetic energy equals its rest energy? v = 4yb8 /k;tm eob   c

  At what speed will an object's kinetic energy be 25% of its rest )os)gt lo f.7: + sg,nthnwv3idc*sj(energy? v =    c

  (a) How much work is required to accel-ggp1n .a,w iqerate a proton from rest up to a speed of 0.997c? W =.ig,a1- gwqpn    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 traveling:nzny 8z0at(p $2.60 \times 10^8 \, \text{m/s}$.
KE =    $ \times 10^{-10} \, \text{J}$
p =    $ \times 10^{-18} \, \text{kg·m/s}$

  What is the momentum of a 750-MeV protonk9,b-yy m cn kx yy9kyb1(n4;d (that is, its kinetic energy is 750 MeV)ny ,k9d 9(kmyy4b;byx-c1 nk y?    $\times 10^{-19} \, \text{kg·m/s}$

  What is the speed of a proton accelerated by a c)vo(tjt8lk/tu y-u 8potential difference of 105 MV? v 8ttvtyl ( -/ o8kcuj)u=    c

  What is the speed of an electron whose kinetic energts v 1n;4a*s;)psg hdny is 1.00 MeV? v =    c

  What is the speed of an electron just before it hits a television screen5tp0o2k1 dlts9 sc6; do wg-cd after being ; d-gd l6dtso5csc20o t9pk1waccelerated from rest by the 25,000 V of the picture tube? v =    c

Two identical particles of rest mass q 9ql/l/yuqb9$m_0$ 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 proto2gcvh wg3gb*-pr;k 2 dn ($m_0 =1.67 \times 10^{-27} \, \text{kg}$) whose kinetic energy is exactly half
(a) its total energy, v =    c
(b) its rest energy.v =    c

  What is the speed an irsxpe8rf;*vi)6 z34b tjw*sd 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 accelerated t . 1vfp/d2r4f35s xb2aevn nrdo 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 a prot169eedk dpa .i-yuv*yk5y;cron ($m_0 =1.67 \times 10^{-27} \, \text{kg}$) 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,6kl 2y/qpgn; jpi o*n0 $^{241}\text{Am}$, 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 versusxz4l: n api-7i ,jm/vi momentum for (a) a particle of nonzero rest mass, and (b) a particxi,zip:/vi4a7ln -jm le with zero rest mass.

  What magnetic field intensity is needed to kee,6ymnk 4q;-6 e7uoqqfwau 7rt p 998-GeV protons revolving in a circle of radius 1.0 km (at, say, 6oqu7nw64;u kq qymtrfa,e -7the 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 .cq/rwmd jw, i kan,k-g,l6d.(with respect to the Earth) observes a meteor come from behind and pass her at a speed she 6/.-j wk rq,dm.i,lgda,kcnwmeasures as 0.50c. How fast is the meteor moving with respect to the Earth? u =    c

  Two spaceships leave Earth in opp- 0-z g1xc*pj6ngoh9rv-d r yjosite directions, each with a speed of 0.50c with reszd*1nyj--rv-ogchxjg6 r0 p 9pect 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(v ws z,;aym6v9h2roi . A second spaceship leaves the first v 9i(s z62wovam,y rh;at a speed of 0.87c with 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 vesmr-w1w x:k*b csel approach at a speed of 0.60c. The Enterprise comes to the rescue (Fig. Below), overtaking the aliens while moving directly toward Earth at a speed of 0.90c relative to Earth. What is the relatcxw 1b-w:mk r*ive speed of one vessel as seen by the other? u =    c

  A spaceship in distress sends out two escape pods in opposite directions. One trrbo 6 ritkx3/myn;67 qavels atxin/6r ;7tm3kqy6 bro 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.x6hlharv8/t57ui,g 0 :t( 8gr fxtb nu At the same time, rocket B passes Earth moving 0.95c relative to Earth in the same direction. How fast is B moving rexrnr5, x(7bl a gtuh6/v 88:hgt0uf tilative to A when it passes A? u' =    c

  The nearest star to Earth is Proxima Centauri, 4.3 light-yearsvzhgg +m nf55- 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 faster thanrpd7s) -xpm4o about 0.1c is called relativistic - i.e., for which the correction using special relativity is a significant effect. Determine the speed of an electron in a hydrogen a7 p4p)m sxd-rotom ($v \approx 2.2 \times 10^6 \, \text{m/s}$) 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 uf y )u1kg(6oj(l-bgsd $v$ of an electron whose kinetic energy is 14,000 times its rest energy? You can state the difference $c - v$. Such speeds are reached in the Stanford Linear Accelerator, SLAC.    m/s less than c
(b) If the electrons travel in the lab through a tube 3.0 km long (as at SLAC), how long is this tube in the electrons' reference frame? [Hint: use the binomial expansion.]L =    cm

  How many grams of matter would have to be totally destroyed to run arka0l 7b/-5-;nzmpjudo jdp,et r z-/ 100-W lightbu-pd/ ; pl -ez-5um7rnbzj,/ or0adk tjlb for 1 year? $m_0$ =    $ \times 10^{-8} \, \text{kg}$

  What minimum amount of electro/ehziux5c +0jmna i 4s.d/a: gmagnetic energy is needed 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 in this proc+0/ j4e5:.xu iciz /sgahmnadess.) 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 ligx+ wrjlgy9+v 3e*o /acey gfp/:10on wht collides head on with a positive muon traveling at 50% the speed of light. The two muon+0y1wycpga:/ +jee*rvowgn xo / 39lfs (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 t(z6;qdum 5khproton, 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 neut k;56uhqt zmd(ron decays at rest. KE =    MeV

  The Sun radiates energy at;;;ebl ax1p1n v itucky ,nv02 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 m)usm r5 t:ob zaj3vm ,cp.+2mheasured to have a negative charge and a speed of $2.24 \times 10^8 \, \text{m/s}$. Its momentum is determined to be $1.07 \times 10^{-22} \, \text{kg·m/s}$. Identify the particle by finding its rest mass.
 ----待选择----electronpositron 

  How much energy wouldz ye9 y)d4uxf 3ta5gle 5wbc0; be required to break a helium nucleus into its constituents, two protoy4a9 )del5tf3xzg;5 uewc0yb ns and two neutrons? The rest masses of a proton (including an electron), a neutron, and helium are, respectively, 1.00783 u, 1.00867 u, and 4.00260 u. (This energy difference is 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 traveling 119v:ej (zcp+3hp p0+:p (u z:hgtz kfhc0 km/h as compared to at rest? [Hinft3:j0 ( pguhv z:h +p hze:zpk9+p(cct: use the binomial expansion.]$\frac{\left(m-m_0\right)}{m_0}$ =    $\times 10^{-11}\%$

  Two protons, each having a speed of 0.935c -x wo ,mo0.lxnin the laboratory, are moving toward each other. Deter.x,wo- xlon0m mine
(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 with momenemz8fj(;f .ikq+q ,hv tum $p$ and energy $E$ has a speed given by $v = \frac{pc^2}{E}$.

  The fictional starship Enterprise obtains its powo3m9( jje9vrd 3se.d yer by combining matter and antimatter, achi ed3jej ysv9od3(rm9.eving complete conversion 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 grea-o/mjlwt cgh63iqw v5 0k.0n wter than its rest mass l thcw3j inkvm650q w.wg/o-0 $m_0c^2$ 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 physsbc7d89 d oo.aics believes that he can fit a 15.0-m-long pole into a 12.0-mo7csda9. o8 bd-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 and one mole of oxygen react to form 5epe dts iaur; nak: ,whor-iyk5u 7iu0p66++two moles of water, the energy released is 484 kJ. How much does the mass of the elements decrease a-eap 05eiop6ysrw5rk+ut6nd+h,kuiu7i : ; 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 ar yy98e9w 89mv6eo5gzqtfzuv*e created, traveling 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 relative to thof*ev9 wze 5u89 9tyzvgy6m8qe other particle? u =    c

  An astronaut on a spaceship traveling at 0.75c relative to Ear zbw,zt2,c po5 vmquqw57-2 flth measures his ship to be 25 mlb2-5t 7wzu,vcp,f52 q qmwzo 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 spaceship at a speed of 0.85c away from + d- yyeu+;jsr:b+) va gdqxz:Earth. You send a laser beam toward:ed uzy+x bj-rd:gqy+va)s+; 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 lg(zply g(b od:ui*)3 2xwq p:have a total mass of 150,000 kg. The occupants would like to travel to a star that is 25 light-years away at a speed of 0.60c. To accelerate, the engine of the spaceship changes masq 3lzg:g p:((lypud bix*o)w2s directly to energy. How much mass will be converted to energy to accelerate the spaceship to this speed?    kg
Assume the acceleration is rapid, so the speed for the entire trip can be taken to be 0.60c, and ignore decrease in total mass for the calculation. How long will the trip take according to the astronauts on board?$\Delta t_0$ =   y

  Suppose a 12,500-kg spaceship left Earth at a speed ofax* 1/t5dygj l 96;2ryvya rgf 0.99c. What is the spaceship's kinetic energy? Compare with the total U.S. annual energy consumptionxyg 6v1*tar 59jgd/;ayyrlf2 (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.-1:v b0 ajgkdh0 light-years from Earth. Passengers on the ship want the (one-way) trip to take no more than 1.0 year. Hjha-dbvk1 0g:ow much work must be done on the spaceship to bring it to the speed necessary for this trip? u =    c

  A 1.68-kg mass oscillates on the end of a spring whose s:,c*9o3e+nb g er gl0rwp5wjfpring stiffness constantee +g 5wwr0pn:3jlc f*9,brog is $k=48.7 \, \text{N/m}$. If this system is in a spaceship moving past Earth at 0.900c, what is its period of oscillation according to
(a) observers on the ship, T =    s
(b) observers on Earth? $T_{earth}$ =    s

A pi meson of rest m3 2afgkw p3/)lczjcd-ass $m_\pi$ 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 $KE_\mu = \frac{(m_\pi - m_\mu)^2 c^2}{2m_\pi}$.