Question

005 (part 1 of 4) 10.0 points A block of mass 49 kg slides along a friction- front of it, and moving in the opposite direc- tion with a speed of 13 m/s, is a block of mass 65 kg. A massless spring with spring constant 1566 N/m is attached to the second block as in the figure.

Answer 1

1.

$v=\frac {49\cdot 42-65\cdot 13}{49+65}\: m/s= 10.64\: m/s$

2.

$\frac {1}{2}\cdot 49\cdot 42^2+\frac {1}{2}\cdot 65\cdot 13^2=\frac {1}{2}\cdot 1566\cdot \Delta x_{max}^2$ (Conservation of Energy)

$\Delta x_{max}=7.88\: m$

3.

$v_{1f}=\frac {49-65}{49+65}\cdot 42-\frac {2\cdot 65\cdot 13}{65+49}$

$v_{1f}=-20.72\: m/s$ (opposite to its initial direction)

4.

$v_{2f}=\frac {2\cdot 49\cdot 42}{49+65}-\frac {(65-49)\cdot 13}{49+65}$

$v_{2f}=\34.28\: m/s$ ((opposite to its initial direction)