Question

3. A 529 lbf rock falls 93.4 feet with an 18.3% loss of PE due to air drag/friction. Calculate the velocity of the rock in ft/s the instant before it strikes the earth. Hint: Set PE - RE 4. A spring is compressed 6.18 cm from its at-rest position. The spring is then compressed an additional 4.45 cm. If the spring constant is 254 N/cm, find the amount of work done in compressing the spring. Report the final answer in units of Joule. 5. A piston compresses a gas from 27.8 into 13.9 in. If this process is performed in an isobaric manner at 145 psi, what is the boundary work W. done in units of ft-lbf?

Answer 1

Tnitial PE mgh-529x o.4536 0.0254 P.E loes in P.E 66944.77 J o.183 x C694Y 77 L2250.89 J &50.87 69Y 54 693.88 J x 54 693 & & veleity 21.35 m/s k (Ax) W = 254 x0. o445 X o. 9515 Joules PAV (o.0254 145 X6894.76x (13.93-27 - 307985.84 - 237293.55

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