Laws of Motion, some problems.

  • #1
I'm new to this forum, so Hi!!! :) I have a test on Newton's Laws of Motion, the day after tomorrow and will appreciate any kind of help on these problems. Thank you very much, and nice to meet you all. :)


Q1. A particle of mass m moves with constant speed v on a circular path of radius r. It starts from a point A and makes a 240 rotation when it comes at point B. What is the average force on it during it's motion from A to B? [Ans: (3√3 mv^2)/4πr ]

Q.2 A 1Kg block is kept on a 100 kg block. Coefficient of friction , μ=0.5
What is the frictional force acting on the 1Kg block? [Ans: 0.1N]

(I know this is very simple, but I am always ending up with an answer of 5N. Am I doing something wrong logically or is the answer given wrong?

Q.3 A person stands in contact against the inner wall of a rotor of radius r. The coefficient of friction between the wall and his clothes is μ and the rotor is rotating about vertical axis. What is the minimum speed of rotor so that the person des not slip downward? [Ans: √(g/μr) ]

Answers and Replies

  • #2
One problem per one thread please.

In each problem, use the template.

Show your attempt.

Respect the rules and you will get help.