For Problems 9-14: Two blocks are connected by a massless cord and frictionless pulley as shown below. The 8.0-kg block is placed on a surface with friction. The 8.0-kg block moves 10 cm to the right. 8.0 kg 6.0 kgSHOW YOUR COMPLETE SOLUTION AND WRITE YOUR SOLUTION ON A PAPER13. The magnitude of the work done by friction on the surface to the 8.0-kg block is: a. 7.8 J b. -7.8 J C. 7,744 J d. -7,744 ] e. None of the above14. The magnitude of frictional force computed is: a. 0.78 N b. -0.78 N C. 774 N d. -774 N e. None of the above 15. Which of the following statement/s is/are always true about the relationship between force, spring constant and displacement? Greater force is needed to be able to stretch a spring with greater spring constant compared to a spring with less spring constant. II A spring is compressed if the work is done by the spring. III On the same spring, displacement increases if the force applied increases. a. I only b. I and II only c. I and III only d. None of the above