Block Sliding down a frictionless plane at an angle

A 4.0 kg block is released from rest at the top of a frictionless plane of length 8.0 m that is inclined at an angle of 15° to the horizontal. A cord is attached to the block and trails along behind (assume the cord is massless). When the block reaches a point 5.0 m along the incline from the top, someone grasps the cord and exerts a constant tension parallel to the incline. The tension is such that the block just comes to rest when it reaches the bottom of the incline. (The person's force is nonconservative!) What is this constant tension? Solve the problem twice, once using work and energy and again using Newton's laws and constant acceleration kinematics.
Please solve numerically to find the answer. Please show all work for both ways of solving. Thanks.