8. A box requires a force of 35 N be applied to move it along at a constant velocity. If a person slides it along a surface for a distance of 25 m and takes 4.5 seconds to do so, what work is accomplished and what power is generated? Fama 9. A soccer player exerts a force of 175 N to a 426 g soccer ball over a distance of 0.67 m. What is the change in velocity of the ball if it starts from rest? Fw = mq 10. A 10.0 kg object is dropped from a cliff with a height of 10.0 m. What is the potential energy at the top of the cliff? What is the velocity of the object right before it hits the ground? F = Kx 11. A bow with a spring constant of 345 N/m is drawn back a total of 75 cm. What force is required to do this? 12. What work is done on a box if it is pulled with a force of 220 N by a rope that makes an angle of 350 and it is pulled a total distance of 0.047 km? slope = K Ay 4X spring constant force extension 13. Find the spring constant based on the graph to the left. (This is just like the lab we did with the spring.) Force Vs. Extension Graph Data Points ... . Uncertainty 1 . ... Uncertainty 2 L. of best fit W Force (N ) Force F [N ] N 0.5 0 . 1 0:2 0.3 0.4 0.5 Extension ( in )