A car of weight W is on an inclined road that rises by 100 m over a distance of 1km and applies a constant…

1. $20\mathrm{ }\mathrm{m}{\mathrm{s}}^{-1}$
2. $5\mathrm{ }\mathrm{m}{\mathrm{s}}^{-1}$
3. $15\mathrm{ }\mathrm{m}{\mathrm{s}}^{-1}$
4. $10\mathrm{ }\mathrm{m}{\mathrm{s}}^{-1}$

Solution

$\mathrm{P}=\left(\mathrm{w}\sin \mathrm{\theta }+\frac{\mathrm{w}}{20}\right)10$

$\mathrm{P}=\left(\frac{\mathrm{w}}{10}+\frac{\mathrm{w}}{20}\right)10=\frac{3\mathrm{w}}{2}$



$\frac{\mathrm{P}}{2}=\frac{3\mathrm{w}}{4}=\left(\frac{\mathrm{w}}{10}-\frac{\mathrm{w}}{20}\right)\mathrm{v}$

$\frac{3}{4}=\frac{\mathrm{v}}{20}$

$15\mathrm{m}/\mathrm{s}=\mathrm{v}$

Asked in: JEE Main 2016 (09 Apr Online)

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