A current exists whenever electric charges move. If ΔQ is the net charge that passes through a surface during a time period Δt, then the average current during this time interval is defined as average current = ΔQ Δt = Q2 − Q1 t2 − t1 . If we take the limit of this average current over smaller and smaller time intervals, we get what is called the current I at a given time t1: I = lim Δt→0 ΔQ Δt = dQ dt . Thus the current is the rate at which charge flows through a surface. The current in a wire is defined as the derivative of the charge: I(t) = Q'(t). What does b I(t) a dt represent?

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?

Acrow drops a 0.11kg clam onto a rocky beach from a height of 9.8m. what is the kinetic energy of the clam when it is 5.0m above the ground? what is its speed at that point?

Question 1 (5 pts): what is the maximum distance for which you can you resolve the two individual headlights of an on-coming truck as two separate lights rather than one if the headlights are separated by 2.00 m and your eye has a diameter of 1.00 centimeter? assume a wavelength of 500 nm.