In the figure below, a block of mass m = 4.5 kg slides head into a spring of spr
ID: 2185940 • Letter: I
Question
In the figure below, a block of mass m = 4.5 kg slides head into a spring of spring constant k = 320 N/m. When the block stops, it has compressed the spring by 9.5 cm. The coefficient of kinetic friction between the block and floor is 0.20. (a) While the block is in contact with the spring and being brought to rest, how much work is done by the spring force? 1 J (b) What is the increase in the thermal energy of the block-floor system? 2 J (c) What is the block's speed just as it reaches the spring? 3 m/sExplanation / Answer
work done by spring=0.5*k*x^2=1.44 j work done by friction force=mu*m*g*x=0.838 so the thermal energy=0.838 j work done by all forces =change ke of the block 1.44-0.838=0.5*4.5*v^2-0 v=0.517 m/s