推 anxio:初哥是真男人！ 11/18 12:44
※ 編輯: hiv1225 來自: 222.156.9.4 (11/18 13:08)
推 lupr8838:辛苦你了~ 繼續加油!! 再次拜託你囉~~^^ 謝謝!!! 11/18 15:42
推 Yvonneya:辛苦囉...^^ 11/19 21:25
先跟大家說聲抱歉...雙數題因為書上沒有解答...所以我不確定我寫的對不對...
但單數題確定是對的啦^^
所以先PO題目和單數題詳解...雙數題的詳解我會盡快補PO的^^
(普物組沒有解散喔~~~) by 初
88. A steel ball of mass 0.5kg is fastened to a cord that is 70.0 cm long and
fixed at the far end(一顆球被70公分的線懸掛著，線的尾端被固定住). The ball
is than released when the cord is horizontal (球以類似鐘擺的軌跡被舉起，直
到線成水平)(Fig.10-61). At the bottom of its path, the ball strikes a 2.50kg
steel block initially at rest on a frictionless surface(當球在她軌跡的底部
，她撞到一個靜止在無摩擦力的平面上的方塊). The collision is elastic(彈性碰
撞). Find (a) the speed of the ball and (b) the speed of the block, both
just after the collision.(求方塊與球在剛撞擊過後的個別速度)
89. Two titanium spheres approach each other head-on with the same speed and
collide elastically(完全彈性碰撞). After the collision, one of the spheres,
whose mass is 300g, remains at rest(靜止).
(a)What is the mass of the other sphere?
(b)what is the speed of the two-sphere center of mass (質心速度)if the initial
speed of each sphere is 2.0 m/s?
a. 300╳V－m╳V＝300╳0＋m╳2V => m＝100 ( g )
b. 300╳2－100╳2＝（300＋100）╳V => V＝1 ( m/s )
90.In the two-sphere arrangement of Touchstone Example 10-8(例題10-8 兩懸吊且相
鄰的球A,B，將A以類似鐘擺順勢提高某一段垂直高度後，放手使齊類似鐘擺順原軌跡撞
擊B球), assume that sphere A has a mass of 50g and an initial height of 9.0cm
and that sphere B has a mass of 85g.After the collision, what height is
reached by (a) sphere A and (b) sphere B? After the next (elastic(彈性))
collision, what height is reached by (c) sphere A and (d) sphere B (don’t
use rounded-off values.)
91.The block in Fig. 10-62(圖10-62碰撞前1.6公斤的物體在左邊以速度5.5m/s向右前進
，2.4公斤的物體以速度2.5m/s向右前進。碰撞後1.6公斤的物體速度為V向右，2.4公斤
的物體速度為4.9m/s向右) slide without friction(無摩擦力).
(a)What is the velocity of the 1.6kg after the collision(並寫出其方向)?
(b)Is the collision elastic(彈性)?
(c)Suppose the initial velocity of the 2.4kg block is the reverse of what is
shown. Can the velocity of the 1.6kg block after the collision be in the
direction shown?
a. 5.5╳1.6＋2.5╳2.4＝V╳1.6＋4.9╳2.4 => V=1.9 ( m/s ) (向右)
b. yes
c. no
92.In Fig.10-63(A與B置於一張無摩擦力的桌上，A在左，B在右，且在B的右邊有一面質量
無限大的牆), block A of mass MA, is at rest(靜止) on a long frictionless(無摩
擦力) table that is up against a wall. Block B of mass MB is placed between
block A and the wall and sent sliding to the left, toward to A, with constant
speed VB1. Assuming that all collision are elastic(彈性), find the value of
MB(in terms of MA(用MA表示)) for which both blocks move with the same
velocity after block B has collided once with block A and once with the wall
(在B撞擊A後，B又反彈到牆，又被牆反彈回來，此時A與B有相同的速度). Assume the
wall to have infinite(無限大) mass.
93.A small ball of mass m is aligned(成一直線) above a larger ball of mass M
with a slight separation, and the two are dropped simultaneously from h
(m在M上成一直線，且兩者相鄰，從高度h的地方自由落下). (Assume the radius of
each ball is negligible compared to h.(假設m與M的半徑相對h來說皆可忽略))
if the larger ball rebounds(回彈) elastically(彈性) from the floor and then
the small ball rebounds elastically from the larger ball, what ratio(比例)
m/M results in the larger ball stopping upon its collision with the small
ball(m被M回彈後M靜止)? (The answer is approximately the mass ratio of a
baseball to a basketball.(答案的比例大約等於棒球與籃球的比例))
(b)What height does the small ball then reach?
a. M╳V－m╳V＝M╳0＋m╳2V => 3m＝M => m/M＝1/3
b. 1/2╳m╳(2(√2gh))2(平方)＝m╳g╳h’ => h’＝4h
94.In Fig.10-64, block A of mass MA slides from rest along a frictionless ramp
from a height of 2.50m (A從高度為2.5m的無摩擦力的圓弧軌道上自由滑落)and then
collides with stationary block B(然後撞擊一個靜止的B), which has mass MB=2MA.
After the collision, block B slides into a region where the coefficient of
kinetic friction is 0.500 (撞擊過後，B進入一個動摩擦係數為0.5的區域)and comes
to a stop in distance d within that region(並且在那個區域停止). What is the
value of distance d if the collision is (a) elastic(彈性) and (b) completely
inelastic(完全非彈性)?
95.In Fig. 10-65(A在一個無摩擦力的凳子上向B滑行，且與B發生彈性碰撞。然後B被A撞
後掉下板凳，且A被B反彈後也掉下板凳。A的水平拋射距離為2d，B的水平拋射距離為d),
puck A of mass MA=0.20kg is sent sliding across a frictionless lab bench, to
undergo a one-dimensional elastic collision with stationary puck B. Puck B
then slides off A rebounds from the collision and slides off the opposite
edge of the bench, landing a distance 2d from the base of the bench. What is
the mass of puck B?
a. 0.2╳V＝MB╳V/3－0.2╳2╳V/3 =>MB＝1 ( kg )
96.In Fig.10-66(A從最左邊向右滑行，先撞擊到B，再來B又撞擊C),block A of mass MA
slides along an x axis on a frictionless floor(無摩擦力的地板) with a speed
of VA1=1.00 m/s. Then it undergoes a one-dimensional elastic collision (一維
的彈性碰撞) with stationary block B of mass MB=0.5MA.Next, block B undergoes
a one-dimensional elastic collision with stationary block C of mass MC=0.5MB.
(a) What then is the speed of block C? Are (b) the speed, (c) the kinetic
energy, and (d) the momentum of block C greater than, less than, or the same
as the initial value for block A(C的速度、動能、動量是比A大還是小還是相等?)?
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◆ From: 222.156.9.4
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