Convert the following 1 mi = 1609 m 1 ft = 12 in 1 in = 2.54 cm 1 hr = 60 min 1 min = 60 sec

1) 3900 m = ? mi

2) 40 cm = ? ft

3) 20 mi/hr = ? m/s

4) $15/hr = ? ¢/s

5) 2000 m/year = ? mi/week

Distinguish between linear momentum and angular momentum

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.

If a star is moving toward earth, it is