You are in a windowles9whlj2b /)rg)z w ,lk;mw0zl 2n ipz3ms car in an exceptionally smooth train moving at constant velocity. Is there any physical experiment you can dozl)b w9 m0jzwz3 2),/lriwk lphn2g;m in the train car to determine whether you are moving? Explain. ----待选择----yesno 

You might have had the experience of being at a red light when unk izrk19k7., 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 absolute and relatrzu7.91 kinkk ive motion?

A worker stands on top 3kf0w82xeu(4lp,yn wts.z; a cl) r xfof a moving railroad car, and throws a heavy ball straight up (from his point of view). Ignoring air rel 2x(n8zufw3t) aw fx;4.ycs,lekp 0rsistance, will the ball land on the car or behind it?

Does the Earth really go around the Sun? Or is it a g8owcgy-4 hgp b+h8n3lso valid to say that the Sun goes around the Earth? Discuss in view of the first principle of relativity (that there is no best 4hhogwn+8gbc3g8p -y reference frame). Explain.

If you were on a spaceship traveling at 0.5c away from a star, at what speedq avc-. t-gqj, would the stt-q ,. vag-qcjarlight pass you?

The time dilation effect is sometimes expressed as “moving clocks i61 2:vuhp1x+8md gc (hjjoqgrun slowly.” Actually, this effect has nothing to do with motion affecting the functioning of clocks. What then does it deal wv ojpg2ijd :8ug1+6hqx(1chmith?

Does time dilation mean that time actually passes more slo:g,vu xj80 c m)fw*lnewly in moving reference frnf,x:j0c*m gwlu 8 ve)ames or that it only seems to pass more slowly?

A young-looking woman astronaut has just arrived home from a long trip. She 9 c9)9/gsmw g)h9 dgne5wboyh rushes up to an old gray-haired man and in the ensuing conversation refers to him as her son. How mig9)s no5d cbem w9hg9)/hwg9y ght this be possible?

If you were traveling away from Earth at speed j7j6m.ysx bi.4gzcb6c b3 k4 g0.5c, would you notice a change in your heartbeat? Would your mass, height, or waistline change? What would obseg 746s xjgb3jk.i64mbz .cby crvers on Earth using telescopes say about you?

Do time dilation and length contraction occur at ordinary svckhg+9lyh,r b vj /hq4i-:a5 peeds, say $90 \, \text{km/h}$?

Suppose the speed of light were infinite. What would happen to the relativistic+bkg, 3: - lpz0oxpmxn predictions of length contraction and time dilatip3x z 0bl,gm-+xnk:p oon?

Discuss how our everyday lives would be different if the speed of light were onli)kmy -9tbza7 yba)yz9m- ik t7 $25 \, \text{m/s}$.

Explain how the length contraction and time dilation formulas mightegyd klw685:g :g1hvq ,2drr :d e-vzf be used to indicate that c i: hwqgzyr5r -2 g:g dfvvdked,l1:e8 6s the limiting speed in the universe.

The drawing at the start of this Chapter shows6 x2bl3 adv/ce the street as seen by Mr Tompkins, for whom the s26exabl3vc /dpeed 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 tra0zuo2b q*z t r*wi9 pl*s/zkz)vel at speeds less than c. Does this put an upper limit on the momentum of a0*uz z zz o)2p/lw*r9i*sbqtkn electron? If so, what is this upper limit? If not, explain. ----待选择----yesno 

  Can a particle of nonzero rest mah.v; i ex/d*glss 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 :kf(tp /:tnn-v+n ogtthis mean that a spring has more mass when compressed than when relaxevt nnpf no-t(g +/kt::d? ----待选择----yesno 

It is not correct to say that "matterfs3 d++kgf1uz/jg9ak can neither be created nor destroyed." What mus+ 1zag/3fk+d9gfj suk t we say instead?

  Is our intuitive notion that velocities simply add, ao()m mz vzv0cyjws s/0z6e0l *s we did in Section 3–8, completely wrong?ly)e(mo/ 0vwssm0z vc j*06 zz ----待选择----yesno 

  A spaceship passes you at a speed of 0.750c. You measure its length to be 28.2 (/6ixl1*f go gkx5d;zaksgl17cxb+n m. How l 6+/1zi7ga(n*k lf xgkd1xo ls bx5c;gong would it be when at rest? $L_0$ =    m

  A certain type of elementary pab6tw- -q r;kre *6tqd+bd4wy crticle travels at a speed of $2.70 \times 10^8 \, \text{m/s}$. At this speed, the average lifetime is measured to be $4.76 \times 10^{-6} \, \text{s}$. What is the particle's lifetime at rest?
$\Delta t$ =    $ \times 10^{-6} \, \text{s}$

  Lengths and time intervals depend on the 7 h8coe(pqkw63 gby; kfactor $\beta = \frac{1}{\sqrt{1 - v^2/c^2}}$ 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 125b/zvlp,4u /mf2 .tfft light-years from Earth at a speed of $2.50 \times 10^8 \, \text{m/s}$, what would you measure this distance to be? L =    ly

  What is the speed of a pion if its average l57ul62xo q4s llkk 6yw*d4tyiifetime 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 fast would ys f bmbk78pr;u3+q7t kou have to travel so that to you the distance would be only 35 lk 8p; b+b37sufq km7tright-years? v =    c

  Suppose you decide to travel to a star 85 light-years away atsf .:*h jaeub.i:e ,nq a speed that tells you the distance is onlye..qb, enu:sa*hij:f 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 wga* n,e 7 mf9rxi4,gxcnf rbe -*us+:$11.2 \times 10^3 \, \text{m/s}$. 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 sta4qtx/ 3x )y1smp yp(mmted that starship Enterprise had just returned from a 5-year voya tm3m xs/mpyq4x(1p )yge 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 awaptc+ftcj toczi(3.+55o e ux 5y. How long would it take a spacecraft traveling 0.960c to reach that star from (jop +5it5 5ut zect3+.ccofxEarth, 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 "Fp5 1dd lc hb49u0e5lywerrari" spacecraft at a speed of 0.660c. It is measured in your frame to be 4.80 m lo4b5ypeu0 9lwlc 1 5hddng 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 a ubtij n19qwa:;2arb4verage lifetime, at rest, is9nba1u 24wrb :j; aiqt $2.6 \times 10^{-8} \, \text{s}$. v =    c

  What is the momentum of a proton tra /u..v* wm ti3kka5nuyxd5t1mf--slpveling at $v =0.85c$? p =    $ \times 10^{-19} \, \text{kg·m/s}$

  At what speed will an object’s relativistic q0d e-ixxt8/ +tnoq :mmass be twice its rest mass? v =    c

  A particle of rest mas /h3 hsc,k.2 lxb n k+b*uy;5)ugwsmnjs $m_0$ travels at a speed $v =0.20c$. At what speed will its momentum be doubled? v =    c

  (a) A particle travels a- iqyjd*ohbr*7dp wj7i :1+dwt $v =0.10c$. 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 of a protaoowb+0ixtchj b jwe :iu.5 t;l; (*4hon that accelerates
(a) from 0.45c to 0.90c,    %
(b) from 0.90c to 0.98c?   %

  A certain chemical reaction requiremy s u+2zn wxf)d(e+w6s $4.82 \times 10^4 \, \text{J}$ of energy input for it to go. What is the increase in mass of the products over the reactants?$\bigtriangleup m$ =    $ \times 10^{-13} \, \text{kg}$

  When a uranium nucleus at rest breaks apart in the process known as fii9cu d0fgl+ i2nus61z92i9 j8lw cxoa+zp9pr ssion in a nuclear reactor, the resulting fragments have a t+ c2ux6lza9pfun +89i92gp9i sol1jcdrwi 0z otal 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 irm:az k51b:dj*f ts s6n 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 *uzc6 r*o 3eg(9et9 ctpm2+gkn5cp yna proton in $\text{MeV}/c^2$. $m_0$ =    Mev/$c^2$

  The total annual energy consumption in the United States ir4:9f(:v, ee e8nupwbgv-mb ts 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 convtj9 bbh7yvuo me(by*85xf13yersion 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 kt+/ldw- td f1zinetic energy equals its rest energy? v =z l-f/t +1dtwd    c

  At what speed will an object's kinetic woe9yw;em you;s/.; l energy be 25% of its rest energy? v =    c

  (a) How much work is required to accelerate a proton fromg (5ar p 8;buug*qa8jjq3k;u f/snp*g rest up to a speed of 0.99qpa5ub 8urjg;*u /j(qa gf*8; k3pg sn7c? W =    GeV
(b) What would be the momentum of this proton?p =    $ \times 10^{-18} \, \text{kg·m/s}$

  Calculate the kinetic energy and momentu1 :1-cvwtc7 ecibjp0lm 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 prjn/.h0udb*o woton (that is, its kinetic energy is 750 MeVdun0j hw/b.*o )?    $\times 10^{-19} \, \text{kg·m/s}$

  What is the speed of a proton accelerated by a potential difference of 105 MV? s9h+xkm0/x ws5 ge3zws,e s)t v )xtwkmexse05,+3w sh z/9ss g=    c

  What is the speed of an electron whod9zbwo2 6ui-v8xjc(jse kinetic energy is 1.00 MeV? v =    c

  What is the speed of an electron just before itf op lc8::7is/c8lq unq--cjb hits a television screen after being accelerated from res- si/ub7cq c:folqc:8l8-np jt by the 25,000 V of the picture tube? v =    c

Two identical particles 0t34 htz h6x9um-g oisof 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 proto-/mwd5z72/xvh; k qgwa8 ofysn ($m_0 =1.67 \times 10^{-27} \, \text{kg}$) whose kinetic energy is exactly half
(a) its total energy, v =    c
(b) its rest energy.v =    c

  What is the speed and d)otz9cru p o-q/ p/ fe*2qdr6:vg p64nb1j huthe 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 accab,w(hzs2x6 c 5sal3velerated 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 a pro* q)i,dd k9 k hp/1l/mwmml0fvton ($m_0 =1.67 \times 10^{-27} \, \text{kg}$) 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, 8o(vg, g,du;s.k p mmi$^{241}\text{Am}$, 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 part4. m 4 ibrfhg1sau7;nqicle of nonzero rest mass, and (b) a particle ws. h7q;4unifg a mb14rith zero rest mass.

  What magnetic field intensity is needed to keep 998-GeV proto5t08jr9m juphns revolving in a circle of radius 1.0 km (at, say, the Fermilab synchrotron)? Use the relativistic mass. The proton's rest masspt0rm ujh9 58j 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.g1ua )nkloc apkb0(:+7q dvn450c (with 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 meteor movinqag()7 1opkl uvnck 0n 4d:b+ag with respect to the Earth? u =    c

  Two spaceships leave Earth inxoq zsaa7y s ofm/r31pka55tp 3az1tu- (f-;p opposite directions, each with a speed of 0.50c with respet paa3zqsmy1k1a pf5x(-pau7z5o -r;3o sft/ ct 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.c .gks1ai) l2pm9-kum71c. A second spaceship leaves the first at a speed of 0.87s.9 makc)m2ipu l-g k1c 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 se::wjtiqo : :ages an alien vessel approach at a speed of 0.60c. The Enterprise comes to the rescue (Fig. Below), overtaking the aliens while moving directly towar::og::wt qajid 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 xwuh eqd2697aout two escape pods in opposite directions. One trae2duxwa 9q 6h7vels at a speed $v_1 =-0.60c$ in one direction, and the other travels at a speed $v_2 =+0.70c$ in the other direction, as observed from the spaceship. What speed does the first escape pod measure for the second escape pod? u =    c

  Rocket A passes Earth at a speed of 0.75c. At the same time, rocket B (a1sevykhfvm r)/ 03i passes Earth moving 0.95c relative to Earth in the same direction. How fast is B moving k 3 fi )/as1vey(r0vhmrelative to A when it passes A? u' =    c

  The nearest star to Earth iqbcd ltmx7n-673cnu+t d:9n ls Proxima Centauri, 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, anything traveling fasteo+fqskz72y: or than about 0.1c is called relativistic - i.e., for which the correksy+: 7ozoqf2 ction using special 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 speed q9ygkf8ix3fhw, y e+8 1n /kau$v$ 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 hr23/ polbw (xwould have to be totally destroyed to run a 100-W lightbulb for w2xpr(l3h /bo1 year? $m_0$ =    $ \times 10^{-8} \, \text{kg}$

  What minimum amount of electromagnetic energy is needed to produce an elsej8l .c dent p;.ym49ectron and a positron together? A positron is a particle with the same rest mass as an electron, but has the opposit c9nym l.tdj.e8 ps;e4e 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 3oet u-9dd6ab:3% the speed of light collides head on with a positive ed a6-d uto9:bmuon 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,s8amr (ln -0,e+ft)hom z zm5j an electron, and a neutrino. Assume the nhn e o) ammml8-,zj0zs5(+rtfeutrino'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. KE =    MeV

  The Sun radiates energy at 1s-yjbau w-c a jf)1jfnt6y/hvd*c0. 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 negative charge and a speed oft3 im6 vag1w6zj9rs :b.d7yq i $2.24 \times 10^8 \, \text{m/s}$. 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 nucleu w,rk 9tob/f7js into its constituents, two protons and two neutrons? The rest masses of a proton (including an electron), a neutron, and helium are, respectively, 1.00783 u, 1jof tr,bkw7/9.00867 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 (r;mth w2.c iuk;,pf ral 5:5tgly(y gm*elativistic) mass of a car traveling 110 km/h as compared to at rest? [Hint: use the binomial fkitp(u2, c:5 gmhya5; ;lr.lm wt* gyexpansion.]$\frac{\left(m-m_0\right)}{m_0}$ =    $\times 10^{-11}\%$

  Two protons, each having a speed of 0.935c in the labo ic5o*t9m)y1r r7ccypratory, are moving toward eacc 5)rtpcc1 yo*r 7m9iyh 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 particl9ew5gwv fsywv)s1x7 ooq 2)-k e with momentum $p$ and energy $E$ has a speed given by $v = \frac{pc^2}{E}$.

  The fictional starship Enterprise obtainsb+jwm 0e3lfb db;ct(8 its power by combining matter and antimt;ew3 c0b(lbb mfd+ j8atter, achieving 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 greater than its rese8r 2sdfqn)0ht md2se)f 0qnh8 rass $m_0c^2$ 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 15.00iit kz0 x uh+)p llhs8)5ih)j-m-long pole into a 12.0-m-long barn if he runs fast enough (carrying the pole). Can he do it? Explain in detail. How does this fit pihhui5)lz hikt)0 8j x+s)0l 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 o./ luq5qk 0xaqf oxygen react to form two moles of water, the energy released is 484 l/q5qxu aq0k. 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 crxj(bbox- mkh4)c) 8x oeated, traveling in opposite directions. If the speed of each particle is 0.75c, relative to the laboratb-) mb8xo ) oxjhx(4kcory 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 Ear.rtv:kq2m 1bf th measures his ship to be 25 m lonktr:m. 2qbf 1vg. 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 2r3wf)ovpopjf i: d*2away from Earth. You send a laser beai3: f*)rvodjop2 p w2fm toward the Earth traveling at velocity c relative to you. What do observers on the Earth measure for the speed of the laser beam?

  A spaceship and its occupants have a total mass of 150,000 kt hdmyl vj2q71l z9 n*tyr ;-comjcys,5c,6v9g. 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 mass will be converted to energy to acceler qvjn6z1th*y moy, lc9;,cyv7 s 95tl2jcdm-rate 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 speemg3e5ez i2n/fhe yh :-d of 0.99c. What is the spaceship's kinetic energy? Compare with the total U.S. annual energy consumption (abouthe3yehgzm /e in52 :f- $10^{19} \, \text{J}$). KE =    $ \times 10^{20} \, \text{J}$

  A 42,000-kg spaceship is to travel to the vicinity of a star 6.0trmf* nh1)w f7 light-years from Earth. Passengers on the ship want the (one-way) trip to take no more than 1.0 year. How much work must be done on the spaceship to bring it to the speed necessary for this trip? u =1 t*7hf)mnfw r    c

  A 1.68-kg mass oscillates on the enivfg l3h,c k eb4g73,sj aq,t9d of a spring whose spring stiffness constant is, fg7q,b,ltacjh9 3g34keisv $k=48.7 \, \text{N/m}$. 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 massip,pd ,k itro;4l .)xt cu46rx $m_\pi$ 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 $KE_\mu = \frac{(m_\pi - m_\mu)^2 c^2}{2m_\pi}$.