Physics/Expert Profile

Average Ratings

• Knowledgeability 9.82
• Clarity of Response 9.70
• Timeliness 9.79
• Politeness 9.88

• Number of Questions (in Past 24 Hours) 0
• Max Questions to be Asked (in 24 Hour Period) 2
• Total Questions (since joining AllExperts) 2921
• Volunteer Since 2000-10-22
• Prestige Points 31832

Recent Reviews from Users

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    K = Knowledgeability    C = Clarity of Response    T = Timeliness    P = Politeness

User	Date	K	C	T	P	Comments
Big Dude	11/06/09	10	10	10	10	Thank you!! You helped me understand it .....
Mukul Chakravarty	11/05/09	9	9	10	10
Karina	11/03/09	10	10	10	10	Thank you so much. I didn't think .....
Marc	11/02/09	10	10	10	10	Thank you for answering so quickly, this .....
Brotherbear	10/26/09	10	10	9	10

Recent Answers from James J. Kovalcin

2009-11-07 Speed, time and and distance:

First of all there is no such thing as "all the formulas for the 9th grade"! However, if you a asking specifically about the relationships among distance, velocity, acceleration and time, there are two:

2009-11-06 Speed:

Because this roller coaster is moving in a circular path Newton's 2nd Law applies: SF=m*a where SF is the sum of all the external forces acting on a system and where the acceleration is centripetal a=v^2/R

2009-11-05 Tension and angular velocity:

Because the mass of this pendulum is moving in a circular path it is accelerating and therefore its motion is described by Newton's 2nd Law. Therefore, the sum of the external forces SF acting on this

2009-11-05 Pulleys:

In principle it is only the number of pulleys that matters. However, that completely ignores the reality that friction matters as well. A larger, well constructed pulley [block and tackle] will waste must

2009-11-04 Momentum:

Not at all! Kinetic energy is given by: KE=1/2*m*v^2 while momentum is given by: p=m*v Suppose that one particle has twice the mass of another: m2=2*m1 If their kinetic energies are equal: 1/2*m1*v1^2=1/2*m2*v2^2