First slide

Kinetic friction

Question

In the track shown in figure section AB is a quadrant of a circle of I metre radius. A block is released at A and slides without friction until it reaches B. After B it moves on a rough horizontal floor and comes to rest at distance 3 metres from B. What is the coefficient of friction between floor and body?

Easy

A

$\frac{1}{3}$
B

$\frac{2}{3}$
C

$\frac{1}{4}$
D

$\frac{3}{8}$

Solution

$\begin{array}{r} mgl = \frac{1}{2} {mu}^{2} \Rightarrow u^{2} = 2 g \\ v^{2} = u^{2} + 2 as \Rightarrow 0 = 2 g - 2 a (3) \end{array}$
$\begin{array}{ll} \Rightarrow a = \frac{g}{3} \Rightarrow μ_{k} g = a \\ ∴ μ_{k} g = \frac{g}{3} ∴ μ_{k} = \frac{1}{3} \end{array}$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App