الفصل الثاني(فيزياء): الحركة في خط مستقيم

[نوف18]

السلام عليكم


اذا ممكن

متى استخدم القوانين اللي في الجزء الاول والمعادلات الحركيه سواء اكانت عموديه او افقيه في المسااااائل
مررررره حوست فيها

راجعت امثله الكتاب والحمد اللله فهمتها


بس لما اجي احل اسئله الكتاب اجييييييب العيد اموت ما اعرف احيلها <<< والله مصبيه لو جات بالاختبار


لو سمحت ممكن تفهمني وبالاصح تفهمنا هذه المسائل اللي في الكتاب وتوضحها لنا فضلا لا امرا

checkpcint 1:
here are three pairs of initial and final positions, respec-tively , along a x axis . which pairs give negative displacement:
(a) -3 m , +5m; (b) -3m,-7m ; (c) 7m, -3m ?
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checkpcint 2
the following equations give the position x(t) of particle in four situations ( in each equation , x is in meter, t is in seconds , and t>o ):
(1) x=3t-2 ; (2) x=- 4t^2 - 2 ; (3) x= 2 / t^2 ; and (4) x = -2 .
(a) in which situation is the veloc-ity v of the particle constant ? (b) in which is v in the negative x direction?
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checkpcint 4:
following equations give the position x(t) of particle in four situations: (1) x=3t - 4 ; (2) x= - 5t^3 + 4t^2 +6 ; (3) x= 2/t^2 - 4/t ; (4) x= 5t^2 - 3. to which of these situations do the equations table 2-1 apply ?( معادلات الحركة ع خط مستقيم )

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an automobile travels on straight road for 40 km at 30 km/h. it then continues in the same direction for another 40 km at 60 km/h.
(a) what is the average velocity of the car dur - ing this 80 km trip? ( assume that it moves in the positive x di-rection)
(b) what is the average speed ?
(c) graph x versus t and indicate how the average velocity is found on the graph.

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the position of an object moving along an x axis is given by x=3t-4t^2+t^3, where x is in meters and t in seconds . find the position of the object at the following values of t :
(a) 1 s; (b) 2 s ; (c) 3 s ; (d) 4 s; (e) what is the object's displacement between t=0 and t=4 s ? (f) what is its aver-age velocity for the time interval from t=2s to t=4s ? can be found on the graph.

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a) if a particle's position is given by x=4-12t+3t^2 (where t is in second and x is in meter) , what is its velocity at t=1s?
b) is it moving in the positive or negative direction of x just then?
c)what is its speed just then?
d) is the speed increasing or decreasing just then?
e) is there ever an instant when the velocity is zero?if so .give the if not answer no.
f)is there a time after t=3s when the particle is moving in the negative direction of x? if ,so give the time t : if not answer no

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at a certain time a particle had a speed of 18 m/s in the positive x direction, and 2.4 s later its speed was 30 m/s in the opposite direction. what is the average acceleration of the particle during this 2.4 s interval?

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(a) with what speed must a ball be thrown vertically from ground level to rise to a maximum height of 50 m ?
(b) how long will it be in the air ?
(c) sketch graphs y , v , and a versus t for the ball . on the first two graphs , indicate the time at which 50 m is reached

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