First slide

Work done by Diff type of forces

Question

A block of mass 'm' moving with a speed ' $\large \upsilon$ ' compresses a spring through a distance 'x' before its speed reduces by 25%. The spring constant of the spring is

Easy

A

$\large \frac{{m{\upsilon ^2}}}{{4{x^2}}}$
B

$\large \frac{{3m{\upsilon ^2}}}{{4{x^2}}}$
C

$\large \frac{{7m{\upsilon ^2}}}{{16{x^2}}}$
D

$\large \frac{{9m{\upsilon ^2}}}{{16{x^2}}}$

Solution

$\frac{1}{2}k{x^2} = \frac{1}{2}m\left( {1 - \frac{9}{{16}}} \right){\upsilon ^2}$
$k{x^2} = m\frac{{7{\upsilon ^2}}}{{16}} \Rightarrow k = \frac{{7m{\upsilon ^2}}}{{16{x^2}}}$

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