An air puck of mass 0.034 kg is tied to a string and allowed to revolve in a circle of radius 1.7m on a frictionless horizontal surface. The other end of the string passes through a hole in the center of the surface, and a mass of 2.5 kg is tied to it, as shown. The suspended mass remains in equilibrium while the puck
revolves on the surface.
1.7 m
2.5 kg
0.034 kg
What is the magnitude of the force that
maintains circular motion acting on the puck?
The acceleration due to gravity is 9.81 m/s
2
.
Answer in units of 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.