A lever is used to lift up a 100N weight. The fulcrum is 10cm from the weight. If the effort force is applied at a distance of 50cm from the fulcrum, what is the effort force required to lift the 100N weight?
A) O N
B) 20 N
C) 50 N
D) 100 N

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.