7. A box slides on a smooth (frictionless) horizontal surface, 1.5m above the floor, at a speed of 2.0m/s, as shown in Figure A207. The box then slides down a ramp that makes an angle of 36 with the horizontal and has a coefficient of kinetic friction equal to 0.43. After reaching the end of the ramp, the box continues to slide horizontally on the smooth floor. Use the law of conservation of energy to calculate the final speed (v) of the box. 2111/3 Finll'e A207 8. A block of mass 3.0kg is pressed against a spring (k=3,100N/m) near the bottom of a board inclined at 9228", as shown in gure A208. When released, the block is projected up the incline and the spring expands by 14cm to its normal length. Using the law of conservation of energy, determine the maximum distance (d) traveled by the block up the incline, . in the absence of friction. . when the coefficient of kinetic friction between the block and the board is 0.20. Figure A208 9. A14,000kg tractor traveling north at 21km/h turns west and travels at 26km/h. Calculate the change in the tractor's . kinetic energy. . linear momentum (magnitude and direction)