موضوع مناقشة واجبات فيزياء 101 ترم 111 ‏

1.


111-Q1-Ch09-Lec01








What is the Xcom of the system of three bodies shown in the figure below.
Mass m1 = 4.4kg, m2 = 5.2kg and mass m3 = 3.9kg.

Give your answer in SI units and upto 1 decimal place.












Student Response

Value




Answer:

1.3

100%




Score:

1/1









2.


111-Q2-Ch09-Lec01








Two boys, with masses of 42 kg and 61 kg, respectively, stand on a horizontal frictionless surface holding the ends of a light 23-m long rod. The boys pull themselves together along the rod. When they meet the 61-kg boy will have moved what distance?
Answer in SI units and upto 1 decimal place. Do not write units with your answer.












Student Response

Value




Answer:

9.4

100%




Score:

1/1









3.


111-Q3-Ch09-Lec01








Two 14-kg blocks A and B are tied together with a compressed massless spring between them. They are thrown from the ground with an initial velocity of 35m/s, 45o above the horizontal. At the highest point of the trajectory they become untied and spring apart. Block A falls vertically downward. How far block B would land from block A?
Answer in SI units but do not write units with your answer. Take the value of g=9.8 m/s2.












Student Response

Value




Answer:

125

100%




Score:

1/1











مشكور يا M و ما قصرت و عيدك مبارك مقدما

 

كل عام وانت بخير يا m

 

هذه الحلول للي حاب يتأكد







تنبيه : السؤال الثالث لا تقسم الـRــ على 2.

 

ياشباب السؤال الثالث اقسم r عى اثنين ولا لا ؟؟

 

لاتقسم , بس طبق هذا القانون R=(v^2)/g *sin2angle

 

3/3
اللـحين أقدر أقول إنـي بإجـآزة ^_^
يعطيـكمـ ربـي العـآفية يـآ شبـآب

 

1. 111-Q1-Ch09-Lec02 (Points: 1)
Two bodies, A and B, have equal kinetic energies. The mass of A is four times that of B. The ratio of the momentum of A to that of B is:



1. 1:4

2. 2:1

3. 1:2

4. 4:1

5. 1:1



2. 111-Q2-Ch09-Lec02 (Points: 1)
A 7.7kg object can move along the x axis. It is subjected to a force F in the positive x direction; a graph of F as a function of time t is shown below where Fmax= 6.4N. Over the time the force is applied the change in the velocity of the object is:









3. 111-Q3-Ch09-Lec02 (Points: 1)
A Ping-Pong ball machine can throw ping-pong balls, each of mass 56.8g, at the wall with a rate of 159 balls/min, and the speed of each ball is 66.5m/s. If those balls rebound from the wall with no change in their speed then what is the magnitude of the average force on the wall?
Give your answer in SI units and upto 1 decimal place. Do not write units with your answer.

 

ATTENTION : I DIDN'T GET MY GRADE YET SO I DON'T KNOW IF MY SOLUTION IS RIGHT OR NOT !

Q1 :
2:1

Q2 :
Area under the curve = Impulse .
so
change in momentum = impulse
after finding the impulse we write
mass * change in velocity = impulse
we write change in velocity = impulse/mass

Q3 :
First of all we have change units :
mass from gram to Kg by multiplying it by 1/1000
unit of "number of balls/min" to "number of balls/sec" by multiplying it by 1/60

then we write
Favg = -(n/change in time) * m * change in velocity

notice : 1) n/change in time = number of balls/sec
2) change in velocity : Vf-Vi

 

الـWeb CT يفتح عندكم؟
صار له من الصباح مب شغال معي..

 

^
ممكن أحد يفيدني، المشكلة ما زالت قائمة.. هل هي بس عندي أو مشكلة من الويب سيتي نفسه؟

 

والله أنا نفس الحالة .. مادري وش السواة والله


أنا خارج الجامعة

 

^^^^^

المشكلة مو موجودة عندي أخوي
انا ساكن بالجامعة

 

أنا فاتح عندي

شيّك يمكن يفتح

 

طيب حل السؤال الأول والثاني كيف طريقته ؟؟؟؟

 

شغال الويب سيتي من داخل الجامعه

أضغط هنا للدخول للويب سيتي

 

-------------------------------------------------

السؤال الأول والثاني اتوقع انهم تمام

لكن الثالث انا شاك في حلك

لان السؤال يقول ما في تغير بالسرعة وبكذا راح يكون التغير صفر ويصير الجواب صفر

نورنا لا هنت

 

بالنسبة للسرعة اتوقع تصير
v2-(-v1)=2v
لانه الاتجاه اتغير

 

اتوقع كذا تمام

شكراً شباب

بس سؤال اخير

الجواب حق السؤال الثالث نحطه بالسالب؟

 

افصل النت واشبكه ثاني وبيضبط معك إن شاء الله
توي جربت ورجع فتح معي، باقي ساعتين قبل نهاية الوقت، محد حل الأسئلة؟

 

Ch09-Lec03

A 2-kg rubber ball is dropped from the window of a building. It strikes the sidewalk below at 10m/s and rebounds up at 10m/s. What is the impulse of the ball? (Take y-axis positive upwards)



1. 40j

2. 20j

3. -40j

4. 0

5. -20j





A 92 kg man lying on a surface of negligible friction shoves a stone away from himself, giving it a speed of 6.1 m/s. If the speed of the man after the shove is 0.002 m/s in the backward direction then what is the mass of the stone?Answer in SI units and upto 3 decimal places. Do not write units with your answer.






65-kg man is riding in a 38-kg cart at 3.6m/s. He jumps off the cart in such a way as to land on the ground with no horizontal velocity. What is the resulting change in the speed of the cart?Answer in SI units and upto 1 decimal place. Do not write units with your answer.