A hockey puck at rest on a very smooth icy surface with negligible friction. It is struck with a hockey puck to the right. It speeds up while it is in contact with the stick. As soon as it loses contact with the hockey stick, it keeps moving with little friction. Shortly after that it hits a rougher icy surface which causes it to slow down and then stop Apply the Work-Energy Principle to the puck for all three phases. Show the FBD for each phase and include
the displacement vector. Explain which force does positive work and which force does negative work and
which force(s) does O work and how that impacts the kinetic energy overall. You can use a table to organize
your work. It is up to you how to proceed as long as you are clear. Again there are no calculations.
For each phase of the motion explain how the different types of energy are changing...are they changing from
potential to kinetic, kinetic to thermal, not changing at all, etc. State whether energy is conserved at each stage
and why or why not. Where does the energy from the original hit go?

American eels (anguilla rostrata) are freshwater fish with long, slender bodies that we can treat as uniform cylinders 1.0 m long and 10 cm in diameter. an eel compensates for its small jaw and teeth by holding onto prey with its mouth and then rapidly spinning its body around its long axis to tear off a piece of flesh. eels have been recorded to spin at up to 14 revolutions per second when feeding in this way. although this feeding method is costly in terms of energy, it allows the eel to feed on larger prey than it otherwise could. 1.a field researcher uses the slow-motion feature on her phones camera to shoot a video of an eel spinning at its maximum rate. the camera records at 120 frames per second. through what angle does the eel rotate from one frame to the next? 2. the eel is observed to spin at 14 spins per second clockwise, and 10 seconds later it is observed to spin at 8 spins per second counterclockwise. what is the magnitude of the eels average angular acceleration during this time? 3. the eel has a certain amount of rotational kinetic energy when spinning at 14 spins per second. if it swam in a straight line instead, about how fast would the eel have to swim to have the same amount of kinetic energy as when it is spinning? 4.a new species of eel is found to have the same mass but one-quarter the length and twice the diameter of the american eel. how does its moment of inertia for spinning around its long axis compare to that of the american eel?

An object is located 30.0 cm from a concave mirror. the focal length is 15.0 c,. what is the image distance? a. 30.0 cm b. -10 cm c. 10.0 cm d. -30.0 cm

The rigid beam is supported by the three suspender bars. bars ab and ef are made of aluminum and bar cd is made of steel. if each bar has a cross-sectional area of 450 mm2, determine the maximum value of p if the allowable stress is (σallow)st = 200 mpa for the steel and ( σallow)al = 150 mpa for the aluminum. est = 200 gpa and eal = 70 gpa.