## EQTABOT one year ago a block of mass In = 2.5 kg slides head on into a spring of spring constant k = 320 N/m. When the block stops, it has compressed the spring by 7.5 cm. The coefficient of kinetic friction between block and floor is 0.25. While the block is in contact with the spring and being brought to rest, what are (a) the work done by the spring force and (b) the increase in thermal energy of the block-floor system? (c) What is the block's speed just as it reaches the spring?

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1. mohammed213

2. Will-i-am

(a) 240 joules....(b)????.....(c)?????????

3. iamsmarterthanyou

lol dude ur awesome...lol that was myself

4. iamsmarterthanyou

wait a second

5. govindraj

obviously work done by spring force is change in spring potential which is $kx ^{2}\div2$ increase in thermal enegry is the work done by frictional force which is $\mu \times normal \times displacement$ adding the above two we get the energy of the block just as it approches the spring $w = mv ^{2}/2$(kinetic work therom)