The 2-kg block is subjected to a force having a constant direction and a magnitude F = (30...

The 2-kg block is subjected to a force having a constant direction and a magnitude F = (300/(1 + s)) N where s is in meters. When s = 4 m, the block is moving to the left with a speed of 8 m/s. Determine its speed when s = 12 m. The coefficient of kinetic friction between the block and the ground is μk = 0.25.