One day, Mike’s friend was performing their respective experiments given by their teacher. While sitting in the practical lab instead of performing

experiment, Mike was playing with his meter scale. All the sudden, he held

the scale in his hand and started moving in front of tube-light, then he observed the seven colours of white light.
(a) What is the band of seven colours called?

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.