A780g, 50-cm-long metal rod is free to rotate about a frictionless axle at one end. while at rest, the rod is given a short but sharp 1000n hammer blow at the center of the rod, aimed in a direction that causes the rod to rotate on the axle. the blow lasts a mere 2.5ms.

what is the rod's angular velocity immediately after the blow? the book gives the answer 8.0rad/s

Which term best describes the phrase “something that happens”?

An air standard cycle with variable specific heats is executed in a closed system and is composed of the following four processes. 1-2 isentropic compression 100 kpa and 22°c to 600 kpa 2-3 v=constant heat addition to 1500 k 3-4 isentropic expansion to 100 kpa 4-1 p=constant heat rejection to initial state (a) show the cycle on p-v and t-s s (b) calculate the net work output per unit mass (409 kj/kg) (c) determine the thermal efficiency (47.9%)

Whenever the net force on a moving object is zero its acceleration is