You are in a windowless car in an exceptionally smooth train moving at constant kc(sq ld4h *aff33- kivelocity. kh l3f( dcq3k-*4s faiIs 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 being at a red light whem,i g/,q s8.gk y./hiqstbwi -n, out of the corner of your eye, you see the car beside you creep forwar.ym8gq/,,./hsgiskqbi iwt- d. Instinctively you stomp on the brake pedal, thinking that you are rolling backward. What does this say about absolute and relative motion?

A worker stands on top of a moving railroad car, aud.sa 1s 5nd;vnd throws a heavy ball straight up (from hssda5nuv1;d. is point 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 that tp4kfx , ou,r*8x6gomwhe Sun goes around the Earth? Discuss in view of to* m6 , gw,4ux8pkxorfhe first principle of relativity (that there is no best reference frame). Explain.

If you were on a spaces 0y ,if2lwd+m .etsw,dhip traveling at 0.5c away from a star, at what speed would the starlight pass ytw+ 0ysfe,.2lmd,dwiou?

The time dilation effect is sometimes expressed as “moving clocks run d1bdsir vi-9o/3 ci5u slowly.” Actually, this effect has ndru c15v o/9bi3sii-dothing to do with motion affecting the functioning of clocks. What then does it deal with?

Does time dilation mean that time actually 1urt.4zv d k8lpasses more slowly in moving reference frames or tzkl41d.t vu 8rhat it only seems to pass more slowly?

A young-looking woman astronaut has just arrived home from a long trip. Shrg 2l8 5aiyhhuur8sf+) +do+gcmp7y, e rushes up to an old gray-haired mg58p 2h a+u+)ruc8hf,mro+ ydi y7slgan and in the ensuing conversation refers to him as her son. How might this be possible?

If you were traveling away from Earth at speed 0.5c,mykmr e;y)ys3ijt0/4 would you notice a change in your heartbeat? Would your mass, height, or waistline change? What would observers on Earth using telescopes say abo kt4)3i ejysmy/;rm0y ut you?

Do time dilation and length contraction occur at ordinat wxm+enpc1a(6r.) c4r pui3/8w gaxjry speeds, say $90 \, \text{km/h}$?

Suppose the speed of light were infinite. What would happen to the relbof j92p9i ra4ativistic predictionopfb92j4ira 9 s of length contraction and time dilation?

Discuss how our everyday lives would be different if the speed of light were onl.,.g0 3:giaw-owe 7lzqqjugz.i: 0wq3gogq-jz, l .7auz gwey $25 \, \text{m/s}$.

Explain how the length contraction andgu (.vhy:qptf q-uo ,2 time dilation formulas might be used to indicate that c is the limiting sp gqv,u:t-ph( ouqyf2. eed in the universe.

The drawing at the start of this Chapter shows the street as seen by Mr*aj*e9mw ci *n Tompkins, for whom than*j* m*iwe9ce 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. Does this put an upper 9amu puqj v/0(limit on the momentum of an electron? If so, what is this upper lia(jq9u m0 v/pumit? If not, explain. ----待选择----yesno 

  Can a particle of nonzero rest mass atti dqa5;uqn.d x4tt 2q6ain 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 thiq u4hhe ktnk9 fr4h7*fm/ l4:ss mean that a spring has more mass when compressed thak*4/4kh4h7thlsef: 9n fru mqn when relaxed? ----待选择----yesno 

It is not correct to say that "matter can neither be created nor dn nmz+5c7 f m(5bf3lscestroyed." What must we say insteacs+5f7bnc 3f (5lmzn md?

  Is our intuitive notion that velocities simply add, z:j *cl5c-egkas we did in Section 3–8, completely wrong5:czkle c*-jg? ----待选择----yesno 

  A spaceship passes you at a speed of 0.750c. You measure b qmgi*ebh6nyw j+82 ,its length to be 28.2 m. How l6*y8 m+biq2gj,hbwn eong would it be when at rest? $L_0$ =    m

  A certain type of elementary particle travels at a speed,t* n tcy (,ea;bgiijrw;vpp*, 6s1m l 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 factor n;/a8 ni 5g8c/pl-cvs*h 3vxno rac ,s$\beta = \frac{1}{\sqrt{1 - v^2/c^2}}$ 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 spe 5btiz( zpas0y-06btqics;:ned 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 li10l w8 o)y9h(db(cyzeql4wz dfetime 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 fy1 9d1 g1rjlcz4c5pqa ast would you have to travel so that to you the distance would be only 35 light-ypj1ylcd 1a9z54qgcr 1 ears? v =    c

  Suppose you decide to travel to a* kp69 lg;5 ,/bhnv+tykbxvpm star 85 light-years away at a speed that tells you the distance is only 25 light-years. Howlbp/;xy,*h kmnv t95v+b pkg6 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 Eart; c0rxy9v;giv/ir2 bi h 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 psg(0j3q fe 5estarship Enterprise had just returned from a 5-year voyage while traveling at 0.8ej5e3(q g0psf4c.
(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 spac8 l+lpq e*gp3lecraft traveling 0.960c to reach that star from Earth, as measured by observerleg3ll+p 8qp* s:
(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" spacecraft aadabn+ aql,0 7i83l-- akrbd it a speed of 0.660c. It is measured in your 7rd+ 0qd3anbk l ai -i8,bala-frame to be 4.80 m long and 1.25 m high.
(a) What will be its length and height at rest?
$L_0$ =    m
the rest height is    m
(b) How many seconds would you say elapsed on your friend's watch when 20.0 s passed on yours? $\bigtriangleup t_0$ =    s
(c) How fast did you appear to be traveling according to your friend?    c
(d) How many seconds would she say elapsed on your watch when she saw 20.0 s pass on hers?   s

  How fast must an average pion be moving to travel b,q kto,bio cn-7y; +v15 m before it decays? The average lq;ocn7t,kv y+b ,b-io ifetime, at rest, is $2.6 \times 10^{-8} \, \text{s}$. v =    c

  What is the momentum oflu3t 0txc g: (*hv1m ;dkf3dki a proton traveling at $v =0.85c$? p =    $ \times 10^{-19} \, \text{kg·m/s}$

  At what speed will an object’s relativistic mass be twice its rest mass? v =px w6zv(fr: ;9q/mn ul    c

  A particle of rest mb0m3 qz-5yniyass $m_0$ travels at a speed $v =0.20c$. At what speed will its momentum be doubled? v =    c

  (a) A particle travel x2sj ry0y6.)rz q,q58a2f ocp7rlpa 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 in momentum of a proton that accelerates b-t9,wrf +v 9b hwzm033d7ccxuibn,h
(a) from 0.45c to 0.90c,    %
(b) from 0.90c to 0.98c?   %

  A certain chemical re0l ijtbo7o 6i-action 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 nucleus3v fgic 49etz- at rest breaks apart in the process known as fission in a nuclear reactor, the resulting frafe -i3c9vz 4tggments 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 j0ylb+ rg(*zii8c.i q f/, tozjoules 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 pa()l9rv1hpjkg wwi 4s+p- i3wroton in $\text{MeV}/c^2$. $m_0$ =    Mev/$c^2$

  The total annual energy consumption in the United48ga 4ftn gm;x d3*vdc 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 gr ;jwin-k n:gm,am 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 partic 68m pr,aoc5fhle when its kinetic energy equals its rest energy? v = fo85c6pa,mrh    c

  At what speed will an object's kinetic energy be 25% nfwl7i) nolqz iq35,c.zrg 39 of its rest energy? v =    c

  (a) How much work is required to accelerate a proton from rest up to . ) kel)rgc(9ru;lh7ay6o scca speed of 0.99; h)c g.l7)9lc6syrecoa(k ru 7c? W =    GeV
(b) What would be the momentum of this proton?p =    $ \times 10^{-18} \, \text{kg·m/s}$

  Calculate the kinetic energy and momentum of a proton tra7+ xvj)nip f2aveling $2.60 \times 10^8 \, \text{m/s}$.
KE =    $ \times 10^{-10} \, \text{J}$
p =    $ \times 10^{-18} \, \text{kg·m/s}$

  What is the momentum ofcmq:x-gh +vqj th6yga-,t4 -g a 750-MeV proton (that is, its kinetic energy is 750 MeV)h- :m y,t4a-x+vtqcgj 6g- hqg?    $\times 10^{-19} \, \text{kg·m/s}$

  What is the speed of a proton accelerated by a potential differencwt) 6q6+y.8kkxybc5ul jhab4e of 105 MV? v6wxjh.y 8 a 6uc+)kkqb 5tlby4 =    c

  What is the speed of an electron whose kinetic energy is 1.8; 6 /)m nzlaa k)x(ezkr2ahdzu: 2irb00 MeV? v =    c

  What is the speed of an electron just before it hitst3it)ob 4;buw a television screen after being accelerat4t3ub o t;)wibed from rest by the 25,000 V of the picture tube? v =    c

Two identical particles of ry*bgl r(9 el9nest 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 proton awgm )ol 1w.d4anoh04 ($m_0 =1.67 \times 10^{-27} \, \text{kg}$) 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 electron 8r;rlrxf 3vj2ogn5x + ($m=9.11 \times 10^{-31} \, \text{kg}$) whose kinetic energy equals its rest energy?
v =    c
p =    $ \times 10^{-22} \, \text{kg·m/s}$

  Suppose a spacecraft of mass 5 n1mv. ,-kqdbna -iud27,000 kg is accelerated to 0.21c.
(a) How much kinetic energy would it have? KE =    $ \times 10^{19} \, \text{J}$

(b) If you used the classical formula for kinetic energy, by what percentage would you be in error?    %

  Calculate the kinetic energy and momomh*nc j37 /c- o9zzxxentum 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 nucleus, yjjemy7 :p 12y$^{241}\text{Am}$, 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 kin.hwcgl-hz 3 uy+xb8/he12 ehdg 0bt 6qetic energy versus momentum for (a) a particle of nonzero rest mass, and (b) a particb6x- ghb3+ z8eylhhdeuwt h2g/qc0.1le with zero rest mass.

  What magnetic field intensity is needed to keep 998-GeV protons :ke 5x sfb/7mmbiwd .)kdh81crevolving in a circle of radius 1.0 km (at, say, the Fermilab synchrotron)? Use the relativistic mass. The proton's rest mass me 5b8md7ch/idkx w b1.s:kf)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:o-b/4 haipuso 6*bce Earth) observes a meteor come from behind and pass her at a speed she mb- c*ea4u6oib/ s:hp oeasures as 0.50c. How fast is the meteor moving with respect to the Earth? u =    c

  Two spaceships leave Earth*3blz h6mhleqb j +8.l in opposite directions, each with a speed of 0.50c with r l6.* + jqmh8beb3lhlzespect 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 Eabs3-omj tz.g t*za+x1rth traveling 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 respecto*3s-a1bgtzzt .m+x j 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 al*tq ,dd: pevp5d5v md:ien vessel 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 relativvtqv,5 pm:p 5*dd :dede to Earth. What is the relative speed of one vessel as seen by the other? u =    c

  A spaceship in distress sa n faq; 0o5(gz (uk*gnczvv02ends out two escape pods in opposite directions. One travels at a spee( gn voz0nk( 2 5f*avugcazq;0d $v_1 =-0.60c$ 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 speedoj t,kra+(fx m5h9iq /7bjm-z of 0.75c. At the same time, rocket B passes Earth moving 0.95c relative to Earth in the same difr qb +omt9-km,a7 jx/h5jz(irection. How fast is B moving relative to A when it passes A? u' =    c

  The nearest star to Earth is Proxima Centauri,*) r;hu2:n fn2fpn 5ixmfd9qr 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 faster than about 0.1c is called rea l gsa l/kwev6i:8w05lativistic - i.e., for which the correction using special relativity is a significant effect. Determine the s5waalk0/ve i8:wsg6 lpeed 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 t0je08kwsl hs;c*q ylmu5 z,6bqqy)8d $v$ 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 / lu9s z99(wf0x5rc4uik0n ud ve3gqu a 100-W lightbulb for 1 u n c/s qizuw 0g9f4e(5vrxu993ukld 0year? $m_0$ =    $ \times 10^{-8} \, \text{kg}$

  What minimum amount of electrq rx;w.86wce bomagnetic energy is needed to produce an electron and68qw r e.bcxw; 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 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 light collides head on ut i9eh5ri;jim(9jk7with a positive muon traveling at 50% the speue9k it7 j(jm hr9;5iied 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 no .:ixsx+9gd ,awomh-xzs c;;eutrino. 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 amongh9;sxg;x.- cszx: a+mw io d,o the three particles when a neutron decays at rest. KE =    MeV

  The Sun radiates energy at a rate of arwz)i )fygm)u-v5oo d ljn:38bout $4 \times 10^{26} \, \text{W}$.
(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 ai,-+zpj- m5ygel rv1znd 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 reqy89 m 8lrz4e1ldbo eo.uired to break a helium nucleus into its constituents, two protons and two neutrons? The rest masses of a proton (including an electron), a neutron, and helium are, 91bo.llz 8e do4y mr8erespectively, 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 trav-ypa0ng h*t+ lwf)k z*eling 110 km/h as compared to at restp+ wl)0g kz*nh f*t-ay? [Hint: use the binomial expansion.]$\frac{\left(m-m_0\right)}{m_0}$ =    $\times 10^{-11}\%$

  Two protons, each havix.bi e- 9gnig:xv8ib(bh s5 p,ng a speed of 0.935c in the laboratory, are moving toward each other. i(ix bgi5. hev xb 8ps9,-nbg: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 with moczqh:s5 uj ufa ,br3rgq* /p0+*y6ze bmentum $p$ and energy $E$ has a speed given by $v = \frac{pc^2}{E}$.

  The fictional starship Enterprise obtains its power by combining m2 q3wfzt 7hgqwn+q.f2w. l3xmatter and antimatter, achieving cof3nw+wz.mqf w xl.32htq gq7 2mplete 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 twxaj:ru1gpw9ey:kr1g3d q 82 han its rest m1eyr:9 u1rg:kxpg adw w832qj ass $m_0c^2$ 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 gqo 76n+ 13yhyzdnh(i a 15.0-m-long pole into a 12.0-m-long barn if h7 q(z+dh3h nio g61nyye 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 oxygenv::qd.v2:8t* v hlutee7+ giok9el w v react to form two moles of water, the energy release.hou:dkl7v92vqv+wlvg 8 ::te ti e*ed 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 parma;m* * ;w(dxebfie *tticles are created, traveling in opposite directions. If the speed of each fi(**d bt;a*mwm;ex eparticle is 0.75c, relative to the laboratory frame of reference, what is one particle's speed relative to the other particle? u =    c

  An astronaut on a spaceship trl/r m -z)m9s:ob9uy5b aiha n1aveling at 0.75c relative to Earth measures his shimib5lr -:uz mhs9nyoa 91)ab/ p to be 25 m 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 a9aw656/f ur zhksdby yn 94p3m0h:inq speed of 0.85c away from Earth. You send a laser beam toward the Earth traveling at velocity c relative to you. What do obhzad yfin6 3/m6y r99p:4 s nk0u5hqwbservers on the Earth measure for the speed of the laser beam?

  A spaceship and its occupants have a total mass of 150,000 kg. The occupah .pr5yrfd fvlfu6-(:nts 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 fyr hfpvl f6-(r.5ud: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 srk215v9 ahus bpeed of 0.99c. What is the spaceship's kinetic energy? Compare with the total U.S.sak9u12hv5 br annual energy consumption (about $10^{19} \, \text{J}$). KE =    $ \times 10^{20} \, \text{J}$

  A 42,000-kg spaceship is to travel to tvb i,81ndeeuzg4,v 5phe vicinity of a star 6.0 light-years from Earth. Passengers on the ship want the (one-way) trip to take no more than 1.0 year. How much work md5 4uepz1v,ev,ni8bg ust 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 spring stiffness cxdwpjz 739tz,*n;n voonstant is9z*nvn 37jdzop; x wt, $k=48.7 \, \text{N/m}$. 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 mazqn 5y34+yzzass $m_\pi$ 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 $KE_\mu = \frac{(m_\pi - m_\mu)^2 c^2}{2m_\pi}$.