المساعد الشخصي الرقمي

مشاهدة النسخة كاملة : اسئله الحركة في خط مستقيم



NONETA
11-14-2009, 10:59 PM
سلام عليكم

عندي جم سؤال وان شاء الله يكون عندكم الحل له ولا تخيبون ظني

As you look out of your dorm window, a flower pot suddenly falls past. The pot is visible for a time , and the vertical length of your window is . Take down to be the positive direction, so that downward velocities are positive and the acceleration due to gravity is the positive quantity .

Assume that the flower pot was dropped by someone on the floor above you (rather than thrown downward).

From what height above the bottom of your window was the flower pot dropped?
Express your answer in terms of , , and .


سؤال الثاني

A man is running at speed (much less than the speed of light) to catch a bus already at a stop. At , when he is a distance from the door to the bus, the bus starts moving with the positive acceleration .
Use a coordinate system with at the door of the stopped bus.http://session.masteringphysics.com/problemAsset/1007720/17/6040.jpg

What is , the position of the man as a function of time?
Answer symbolically in terms of the variables , , and .

What is , the position of the bus as a function of time?
Answer symbolically in terms of and .

Inserting the formulas you found for and into the condition , you obtain the following:

, or .

Intuitively, the man will not catch the bus unless he is running fast enough. In mathematical terms, there is a constraint on the man’s speed so that the equation above gives a solution for that is a real positive number.

Find , the minimum value of for which the man will catch the bus.

Express the minimum value for the man’s speed in terms of and .

السؤال الثالث

A motorcycle is following a car that is traveling at constant speed on a straight highway. Initially, the car and the motorcycle are both traveling at the same speed of 42.0 , and the distance between them is 55.0 . After = 4.00 , the motorcycle starts to accelerate at a rate of 4.00 . The motorcycle catches up with the car at some time .http://session.masteringphysics.com/problemAsset/1006750/21/1006750.jpg

How long does it take from the moment when the motorcycle starts to accelerate until it catches up with the car? In other words, find .
Express the time numerically in seconds.

How far does the motorcycle travel from the moment it starts to accelerate (at time ) until it catches up with the car (at time )?
Answer numerically in meters.


السؤال الرابع

Two cars travel on the parallel lanes of a two-lane road. The cars’ motions are represented by the position versus time graph shown in the figure. Answer the questions using the times from the graph indicated by letters.

http://session.masteringphysics.com/problemAsset/1011348/21/1011348.jpg

At which of the times do the two cars pass each other?

At which of the lettered times, if any, does car #1 momentarily stop?

At which of the lettered times, if any, does car #2 momentarily stop?

At which of the lettered times are the cars moving with nearly identical velocity?

السؤال الخامس

Learning Goal: To learn to read a graph of position versus time and to calculate average velocity.


In this problem you will determine the average velocity of a moving object from the graph of its position as a function of time . A traveling object might move at different speeds and in different directions during an interval of time, but if we ask at what constant velocity the object would have to travel to achieve the same displacement over the given time interval, that is what we call the object’s average velocity. We will use the notation to indicate average velocity over the time interval from to . For instance, is the average velocity over the time interval from to .http://session.masteringphysics.com/problemAsset/1006743/14/M1K_av_0v1.jpg

Consulting the graph shown in the figure, find the object’s average velocity over the time interval from 0 to 1 second.
Answer to the nearest integer.

Find the average velocity over the time interval from 1 to 3 seconds.
Express your answer in meters per second to the nearest integer.

Now find .
Give your answer to three significant figures.

Find the average velocity over the time interval from 3 to 6 seconds.
Express your answer to three significant figures.

Finally, find the average velocity over the whole time interval shown in the graph.
Express your answer to three significant figures.



السؤال السادس

In a ballistocardiograph, a patient lies on an extremely low friction horizontal table. At each heartbeat, a volume of blood is accelerated by the heart toward the head along the ascending aorta. In response, the patient’s body recoils in the opposite direction. This motion is detected by sensitive accelerometers attached to the table. (The table is then brought to rest and returned to equilibrium before the next heartbeat.)

http://session.masteringphysics.com/problemAsset/1013192/9/1013192.jpg

A graph of acceleration of the table versus time, termed a ballistocardiogram, is generated. Based on these measurements, the acceleration of the blood ejected by the heart can be determined. Patients with low blood accelerations generally have weakened heart muscles.
A sketch of a single cycle of a ballistocardiogram is given in the figure. Acceleration and time have been measured in unknown units.

At what time is the speed of the table (and hence the speed of the blood in the opposite direction) a maximum?


وتم بحمدلله

واذا ما فهمتوا حق الانكلش تتقدرون ترجمونه وتحلونه بعدين

وسوري عذبناكم وياي

وبس ودمتم سالمين

NONETA
11-20-2009, 07:33 PM
اشدعوا 56 رد ولا جواب

زعلتوني منكم

ما هقيتها منكم

هيفاء
11-20-2009, 08:33 PM
السلام عليكم ورحمة الله وبركاته
أهلا وسهلا بك في المنتدى
بصراحة انا من الجزائر واللغة الإنجليزية ليست مستعملة مثل الفرنسية
يعني ندرس فرنسي
ياريت لو تعرب الأسئلة
سأحاول الترجمة أولا ومن ثم إن كانت لدي إجابة سأوافيكم بها
ان شاء الله المنتدى زاخر بأساتذة ماشاء الله عليهم
ان شاء الله تلاقي جواب في أقرب وقت