Radiation from the sun reaching earth (just outside the atmosphere) has an intensity of 1.43 kw/m2. (a) assuming that earth (and its atmosphere) behaves like a flat disk perpendicular to the sun's rays and that all the incident energy is absorbed, calculate the force on earth due to radiation pressure. (b) for comparison, calculate the force due to the sun's gravitational attraction. assume that the speed of light and earth radius are 2.998 × 108 m/s and 6.37 thousand km respectively.

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.