Ask Physics http://www.askphysics.com Doubts in Physics answered Tue, 14 May 2013 08:30:34 +0000 en-US hourly 1 http://wordpress.org/?v=3.5.1 AskPhysicshttp://feedburner.google.com Average Speed and Average Velocity http://feedproxy.google.com/~r/AskPhysics/~3/fpLdBw8uW9w/ http://www.askphysics.com/average-speed-and-average-velocity/#comments Tue, 14 May 2013 08:30:14 +0000 admin http://www.askphysics.com/?p=4727 The average velocity of a particle is zero but not its average speed. is it possible?

Asked Prashant

Answer:

Yes, it is possible. As you may probably know, Average speed is the ratio of distance traveled by a body to the time taken whereas average speed is the ratio of displacement to the time taken. The displacement made by a body can be zero when the body returns to its original path. abut, the distance which the total length of the path followed by the body cannot be zero.

Therefore the average velocity of a particle is zero but not its average speed. is it possible?

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]]> http://www.askphysics.com/average-speed-and-average-velocity/feed/ 0 http://www.askphysics.com/average-speed-and-average-velocity/ Force between charged rods: A Problem from electrostatics http://feedproxy.google.com/~r/AskPhysics/~3/bRHOiTx33jc/ http://www.askphysics.com/force-between-charged-rods-a-problem-from-electrostatics/#comments Tue, 14 May 2013 08:20:20 +0000 admin http://www.askphysics.com/?p=4723 Two mutually perpendicular long straight conductors carrying uniformly distributed charges of linear charge densities (D1) and (D2) are positioned at a distance a from each other. What is the force between them?

Posted by Harsh

]]> http://www.askphysics.com/force-between-charged-rods-a-problem-from-electrostatics/feed/ 0 http://www.askphysics.com/force-between-charged-rods-a-problem-from-electrostatics/ MCQ from electrostatics http://feedproxy.google.com/~r/AskPhysics/~3/A-ydi6WAXjk/ http://www.askphysics.com/mcq-from-electrostatics/#comments Fri, 10 May 2013 05:17:56 +0000 admin http://www.askphysics.com/?p=4718 Two charges of equal magnitudes & at a distance r exert a force F on each other.if the charges are halved and a distance b/w them is doubled then new force acting on each charge?
1. F/8
2. F/4
3. 4F
4. F/16

Posted by Reghu

Members and visitors are requested to answer the question with due explanation

]]> http://www.askphysics.com/mcq-from-electrostatics/feed/ 0 http://www.askphysics.com/mcq-from-electrostatics/ What is overturning of a vehicle? http://feedproxy.google.com/~r/AskPhysics/~3/YwHJPodLkJE/ http://www.askphysics.com/what-is-overturning-of-a-vehicle/#comments Fri, 03 May 2013 04:07:09 +0000 admin http://www.askphysics.com/?p=4709 What are the conditions in which a car will overturn? How can I derive the equation for condition of overturning? (for derivation, just tips are enough)

Asked Daniel James

Answer

Read this Doc Circular motion03-04

Refer to this too

The dictionary meaning of overturning:

 Tip (something) over so that it is on its side or upside down: “the crowd overturned cars”

]]> http://www.askphysics.com/what-is-overturning-of-a-vehicle/feed/ 0 http://www.askphysics.com/what-is-overturning-of-a-vehicle/ Momentum http://feedproxy.google.com/~r/AskPhysics/~3/xvYpeZwe6F0/ http://www.askphysics.com/momentum/#comments Fri, 12 Apr 2013 11:56:51 +0000 admin http://www.askphysics.com/?p=4704 I’ve just created this question for my undergraduated students that are going to apply for an engineering institute. I’m not quite sure if it’s a nice question, so I’d like to know your opinions or suggestions about it (and yours solutions, of course!)A flying saucer with mass 5m and radius R is at rest and preparing to destroy our beloved Earth. An aircraft is therefore sent to prevent it and shoots a missile with mass m and velocity v1 at the same plane of the flying saucer. The UFO reacts and launches an intercepting missile of mass m and velocity v2 that makes a 30o angle with the direction of the first projectile. If both projectiles meet after a distance h from the launching point of the second missile and then keep moving together, find the minimal value of v2 for which the aircraft will not hit the target.PS.: Ignore friction and gravitational forcesPlease check the attached picture.
Marcos Valle asked

image

]]> http://www.askphysics.com/momentum/feed/ 0 http://www.askphysics.com/momentum/ Coulomb’s Law http://feedproxy.google.com/~r/AskPhysics/~3/rfesCyM84_A/ http://www.askphysics.com/coulombs-law/#comments Tue, 09 Apr 2013 12:20:27 +0000 admin http://www.askphysics.com/?p=4701 in the equation as given in the attached file why do we take the constant as given and what is meant by f is inversely proportional to 4 pi e0 please explain

6ef87591382929117d7f8e3bc1edc75e.png

 

 

]]> http://www.askphysics.com/coulombs-law/feed/ 0 http://www.askphysics.com/coulombs-law/ Newton’s law of gravitation http://feedproxy.google.com/~r/AskPhysics/~3/7TZuxz4DmIw/ http://www.askphysics.com/newtons-law-of-gravitation/#comments Tue, 09 Apr 2013 12:17:04 +0000 admin http://www.askphysics.com/?p=4698 my question is that in the famous equation f= m1Xm2/r2 i understand the derivation but why do we take the product of the 2 masses and the distance between and not the sum ?

Asked Ojal

Answer: This is based on the observations. The law is experimentally verified.

]]> http://www.askphysics.com/newtons-law-of-gravitation/feed/ 0 http://www.askphysics.com/newtons-law-of-gravitation/ Problem from motion of connected systems http://feedproxy.google.com/~r/AskPhysics/~3/J6MwKtsNjR0/ http://www.askphysics.com/problem-from-motion-of-connected-systems/#comments Tue, 09 Apr 2013 12:12:57 +0000 admin http://www.askphysics.com/?p=4691 Two blocks of masses 10kg and 4kg are connected by a light spring lying on a smooth horizontal surface. An impulse gives a velocity of 14m/s to the heavier block in the direction of the lighter block. What is the velocity of the center of mass.

 

Posted by Sreedhar M

 

]]> http://www.askphysics.com/problem-from-motion-of-connected-systems/feed/ 0 http://www.askphysics.com/problem-from-motion-of-connected-systems/ Drift velocity and time taken to light up http://feedproxy.google.com/~r/AskPhysics/~3/NYNtz1W0bXk/ http://www.askphysics.com/drift-velocity-and-time-taken-to-light-up/#comments Mon, 08 Apr 2013 12:14:57 +0000 admin http://www.askphysics.com/?p=4688 As we know that the drift velocity of electron is 1mm/sec…if a bulb is at 50cm then how does it light up so fast within a fraction of second?

Asked Padhy

]]> http://www.askphysics.com/drift-velocity-and-time-taken-to-light-up/feed/ 0 http://www.askphysics.com/drift-velocity-and-time-taken-to-light-up/ Efficiency of Air conditioner http://feedproxy.google.com/~r/AskPhysics/~3/nxHkifrIFQ4/ http://www.askphysics.com/efficiency-of-air-conditioner/#comments Mon, 25 Mar 2013 00:48:22 +0000 admin http://www.askphysics.com/?p=4675 someone designed an air conditioner that takes 500J of thermal energy from a cold room and exhausts 500J of thermal energy into the outside air. The energy is conserved, so the system should work.  Is such a system feasible or are we optimistic about this new design. Why or why not?

asked praveen kumar

Aparelho de ar condicionado

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