Question

Block moves with decreasing speed [20 points) A block on a frictionless table is connected to a spring. A hand pushes the block until it reaches point, compressing the spring. The block moves from point P to point Q with decreasing speed. For the questions below, consider the system of the block and the spring. fridionkes/VZU surface P Q A. (5 pts) For an instant when the block is between point P and point Q, list all forces acting on the block-spring system. For each force, indicate the object exerting that force and the type of force (as per our usual notation). B. [5 pts) For each force you listed in part A, state whether the work done by that force is positive, negative, or zero as the block moves from P to Q. Explain. C. [5 pts) As the block moves from point P to point Q. does the kinetic energy of the block- spring system increase, decrease, or stay the same? Explain, and be sure to resolve any inconsistencies. D. [5 pts) As the block moves from point P to point Q, does the total energy of the block-spring system increase, decrease, or remain constant? Explain.

Answer 1

AY from fibede F = Force exerted by hand F = ing= gravitational force F = spring force N= Normal force Since we know that wita Fd cost Work done by Fn = the because ork done by E= 0 because vark done by Ę = -re because Work done by N= 0 because o=0° hence cose= the o=90 hence cost=0 o = 180° hence cose =-v- o=90° here cose=0 Work ey While moving forom pto & it's kinetic energy will decrease because speed of block is decreasing and We know that kE is directly proportional to 1² (speed) Totel there system energy will remain constant because isn't any dissipative force present in this