Question

Figure shows a spring fixed at the bottom end of an incline of inclination ${37}^0.$ A small block of mass 2 kg starts slipping down the incline from a point 4.8 m away from the spring. The block compresses the spring by 20 cm, stops momentarily and then rebounds through a distance of 1 m up the incline. Find (a) the friction coefficient between the plane and the block and (b) the spring constant of the spring. Take $g=10m/s^2.$

• A. $V_d=1.5\times {10}^{-3}m/sec$
• B. $V_d=2.9\times {10}^{-3}m/sec$
• C. $V_d=2.5\times {10}^{-3}m/sec$
• D. $V_d=3.5\times {10}^{-3}m/sec$

Answer 1

The correct option is C $V_d=2.5\times {10}^{-3}m/sec$

$I=40A$
$A={10}^{-6}{m}^2$
$N={10}^{29}$
$V_d=?$
$I=NeA{V}_d$
$40={10}^{29}\times 1.6\times {10}^{-19}\times {10}^{-6}\times V_d$
$V_d=\frac{40}{{10}^{29}\times 1.6\times {10}^{-19}\times {10}^{-6}}m{s}^{-1}$
$V_d=2.5\times {10}^{-3}m{s}^{-1}$