Ignoring air resistance, the horizontal component:bp 1w/h k2xdh of a projectile's velocity

  A ball is thrown with a velocity of 20 m/s at an iif6 zjc*z+sq g .2:zxangle of $60^{\circ}$ above the horizontal. What is the horizontal component of its instantaneous velocity at the exact top of its trajectory?

  Ignoring air resistance, the horizontal component of a+gyckgo,,ic2 0zpjy3 ce95m w projectile's acceleration 0j32co, p9c zmcewk+giygy5,

  A soccer ball is kicked with a velocity of 25 m/s at an angle ofx:3hhej yx24yn 6 u5e + hhsgw-no+i4n $45^{\circ}$ above the horizontal. What is the vertical component of its acceleration as it travels along its trajectory?

  If the acceleration vec qp* bspdn4wxl; m/5:utor of an object is directed anti-parallel to the velocity vq5mp/d4* su:xw; n pblector,

  If the acceleration of an object is always directed perpendicular to its velocit hz0skyu rc96s..(x c4:nfcmjy,94z6ks j:cu (.hy 0 scfcrmnx.

  At what angle should a water-gun be aimed in 0x ()ntug pkblcx.lo67l 2n)jorder for the water to land with the greatest horizontal .ckt6270gun( ))p lxjllob nxrange?

  An Olympic athlete throws a javelin at fourfh n :seva1(/pme3i6 e different angles above the horizontal, each with the sapms/1e6hef( a n: 3eivme speed: $30^{\circ}$, $40^{\circ}$, $60^{\circ}$, and $80^{\circ}$. Which two throws cause the traveling to land the same distance away?

  You are throwing a ball for thena xd,p/ qj7uqswj.+4 second time. If the ball leaves your hand with twice the velocity it had on your first throw, its horizontal range R (compared to your first serjnus4jp/qaqx+d7. w, ve) would be

  A ball is thrown at an original speed of 8.0 m/s at an angle of rsif oyg uz+5r:;.3pi$35^{\circ}$ above the horizontal. What is the speed of the ball when it returns to the same horizontal level?

  When a football in a field qb.bj+gwl a a95m.j+dgoal attempt reaches its maximum height, how does its speed compare to its inba +dj9gajb.+.mqw5litial speed?

  A stone is thrown horizontally from the top of / m r3+gotbbnv7: zj7 tebce+7a tower at the same instant a ball is dropped vertically. Which object is traveling faster when it hits the level ground b/vezg: er+7 3+nmbcjbtt 7o7 below?

  A bullet is fired horizontally, and at the +/rr l1vd qdr9same instant a second bullet is dropped rv/dqrr9l+ 1d from the same height. Ignore air resistance. Compare the times of fall of the two bullets.

  A plane flying horizontally at a z*khxrgi/mjq1ot,1 6m(,ezu z pl ;b3speed of 117.1 m/s and at an elevation of 165 m drops a package. 5.3 seconds later it drops a second package. How far apart will the tph*3jx1zrlb, o(zzu6 i,mqt ;/g1 k emwo packages land on the ground?

  A package of supplies isu+-mwm(e2eh 0 cbo2ef dropped from a plane, and one second later a second package is dropped. Neglecting air resistance, the distance between the f + m(2h bcw2e-meof0uealling packages will

  A pilot drops a bomb from a plane flying h ,x,w9:p) :gwoy wiaivw.nj/ horizontally at a constant speed. Neglecting air resistance, when the biay .ivhjw9wx n,gw) :,op/w :omb hits the ground the horizontal location of the plane will

  The acceleration of gravity on the *kdz ooz,,5eo Moon is only one-sixth of that on Earth. If you hit a baseball on the Mooek*5 ,,zodozon with the same effort (and at the speed and angle) that you would on Earth, the ball would land

  You are traveling at 55 mi/h in the +x agn;wwnzo) t88b c nx,3xis relative to a straight, level road and pass a 8o3c znn; tw)b,gn8wxcar traveling at 45 mi/h. The relative velocity of your car to the other car is

  You are trying to cross a river that flows due south with a strong l63yw6au 1xbp gv2*ub8 gy9etcurrent. You start out in your motorboat on the east bank desiring to reach the west bank directly west from your starting point. You should y6 uug3y pw6 1*aet8vx92bgbl head your motorboat

  Your motorboat can move ab sj 8j2 q7.h3qh1munht 30 km/h in still water. How much time will it take you to move 12 km downstream, in a river flowing u.b8 q17qn3 j hs2mhjhat 6.0 km/h?

  If a ball is thrown with a velocity of 25cs.zky. e1p/w m/s at an angle of $37^{\circ}$ above the horizontal, what is the vertical component of the velocity?

  A stone is thrown horizontally with an initial speed o9o dgjx84bym7+ghk 0of 27 m/s from the edge of a cliff. A stop watch measures the stone's trajectory time from the top of the cliff to the bottom to be 4.5 s.go9g +j k0oxdb y8hm47 What is the height of the cliff?

  A girl throws a rock horizontally, with a velocity of 20 m*qtsu(+d .sff4ik b /q/s, from a bridge. It falls 11 m to the water below. How far does the rock travel horizo*ks(i +b qff uqd4./stntally before striking the water?

  A ball thrown horizonrrowj 1l/k59bgshecrmw6- --tally from a point 24 m above the ground, strikes the ground after traveling hor jw /rh ck1gr-9lw-s6r5-bmeoizontally a distance of 22 m. With what speed was it thrown?

  A jumper in the long-jump goes into the j98jshurzwg- a7,b lb)ump with a speed of 12 m/s at an angle w)lrs89bbjh a7,z u-gof $20^{\circ}$ above the horizontal. How long is the jumper in the air before returning to the Earth?

  A jumper in the long-jump goes into the jungc9/h p1r:,qy91uefm7 uo kzmp with a speed of 12 m/s at an angle offgqr1umun9 c h1z pk7 o9/,y:e $32^{\circ}$ above the horizontal. How far does the jumper jump?

  A projectile is launched with an in:r sc:nc/(wf2*zuq4jve+ ew r itial velocity of 54.4 m/s at an angle of $37.9^{\circ}$ above the horizontal. How far does it travel?

  A projectile is launched with an initial velocity of 24.6 hsr zy(4ipg u87g s;-nahb9 ,vm/s at an angle of $44.7^{\circ}$ above the horizontal. What is the maximum height reached by the projectile?

  A rifle bullet is fired at an a2)m 6fiq i9.zwd9land ;d nqn1ngle of $30^{\circ}$ below the horizontal with an initial velocity of 800 m/s from the top of a cliff 80 m high. How far from the base of the cliff does it strike the level ground below?

  A projectile is shot horizontally at t+m l/g4 ll,af 24.2 $m/s$ from the roof of a building 50.3 $m$ tall.
(a) Determine the time necessary for the projectile to reach the ground below.  (数值)  $s$
(b) Determine the distance from the base of the building that the projectile lands.  (数值)  $m$
(c) Determine the horizontal component of the velocity just before the projectile reaches the ground.  (数值)  $m/s$
(d) Determine the vertical component of the velocity just before the projectile reaches the ground.  (数值)  $m/s$

  A projectile is fired fro+jpae2 53-y,p 9t fp j-x8e*uwdb xbycm ground level with an initial speed of 49.8 m/s at an angle o wp-p*xu-e+ x9 ybat83d2 feb5cp,jyjf $45.6^{\circ}$ above the horizontal.
(a) Determine the time necessary for the projectile to reach its maximum height.  (数值)  $s$
(b) Determine the maximum height reached by the projectile.  (数值)  $m$
(c) Determine the horizontal and vertical components of the velocity vector at the maximum height. horizontal:  (数值)  $m/s$ vertical:  (数值)  $m/s$
(d) Determine the horizontal and vertical components of the acceleration vector at the maximum height. horizontal:  (数值)  $m/s^2$ vertical:  (数值)  $m/s^2$

  A fighter plane moving 200 m/s horizi8 r1tew5oaqsnl+*f, ontally fires a projectile with speed 50.0 m/s in a nwe+5 l,f1iqra t8o s*forward direction $30.0^{\circ}$ below the horizontal. What is the speed of the projectile with respect to a stationary observer on the ground?

  A boat, whose speed in still0,k7, p,cyp+pjeejrtky l tos4/: l)3qz:fx o water is 8.0 m/s, is directed across a river with a current of 6.0 m/s. What is the speed of the boat as it crosses thee,:lc z)x+ pkt0yr43j/o: s yjotelpq,fk,7p river?

  The driver of a motorboat that cacso p:4pfvs:+bttq 3 /a57h96mc chm bn move at 17 m/s in still water wishes to travel directlybp: 6fcqm sc 4/3 c 9a5hb+mptvoh7:st across a river 0.9 km wide in which the current flows at 3.6 m/s. How long will it take to cross the river?

  The driver of a motorboat that can move at 10 m/s in still water wishes to tra 0xh d(;dhf3ozvel directly across a narrow straihfd;x od0zh (3t in which the current flows at 5.0 m/s. At what angle upstream should the driver head the boat?

  A swimmer heading directly ac xt-ojdu9* gjvc4uj0 /ross a river 200 m wide reaches the opposite bank in 6 min 40 s. She is swept downstream 480 m. How fastx*co j-u4tju jv/0dg 9 can she swim in still water?

  A swimmer heading directly across a river 200 m wide reach yr,p7dcf1yr1es the opposite bank in 6 min 40 s. She is swept downs 1 f,yyr1cdp7rtream 480 m. What is the speed of the current?

  A boat, whose speed in still water is 1.32 m/s, must aim uzi :x1l h9)pi0x1z rkrpstream at an angle of iz9krl1x h)z:r1xi 0p $20.7^{\circ}$ (with respect to a line perpendicular to the shore) in order to travel directly across the stream.
(a) Determine the speed of the current.  (数值)  $m/s$
(b) Determine the resultant speed of the boat with respect to the shore  (数值)  $m/s$