An electron with a speed of 2.3 ×106m/s collides with an atom of element x. shortly afterward, the atom emits a 1240 nm photon. what was the electron's speed after the collision? assume that, because the atom is so much more massive than the electron, the recoil of the atom is negligible. hint: the energy of the photon is not the energy transferred to the atom in the collision.

Looking at this barometer, is the air pressure high or low? what type of weather would you expect? high, bad low, bad high, good low, good

Emmy kicks a soccer ball up at an angle of 45° over a level field. she watches the ball's trajectory and notices that it lands, two seconds after being kicked, about 20 m away to the north. assume that air resistance is negligible, and plot the horizontal and vertical components of the ball's velocity as a function of time. consider only the time that the ball is in the air, after being kicked but before landing. take "north" and "up" as the positive ‑ and ‑directions, respectively, and use ≈10 m/s2 for the downward acceleration due to gravity.

You have two photos of a person walking. one shows the person at the corner of third and main streets, the other shows the person at the corner of tenth and main streets. there are lampposts at every corner in this town, and the first picture shows it to be 10: 32: 00 exactly. the second picture shows it to be 10: 49: 30. you know three facts: (1) all of the clocks are synchronized; (2) there are exactly 12 equal-sized blocks per kilometer in this town; and (3) the streets that cross main in this area are numbered consecutively, with no interruptions. what is the person’s average speed in kilometers per hour?