A 0.70 kg ball on a 0.20 m string rotates in a circular path in a vertical plane. If a constant angular speed of 3.0 rad/s is maintained, what is the tension in the string when the ball is at the top of the circle? A. 0.8 N
B. 3.33 N
C. 5.64 N
D. 11.6 N

How would you place two electrons on a sphere of radius r so that the electrostatic potential energy is minimized. how would you place three electrons to solve the same problem.

Consider an ordinary, helium-filled party balloon with a volume of 2.2 ft3. the lifting force on the balloon due to the outside air is the net resultant of the pressure distribution exerted on the exterior surface of the balloon. using this fact, we can derive archimedes’ principle, namely that the upward force on the balloon is equal to the weight of the air displaced by the balloon. assuming that the balloon is at sea level, where the air density is 0.002377 slug/ft3, calculate the maximum weight that can be lifted by the balloon. note: the molecular weight of air is 28.8 and that of helium is 4.

Why are graphs useful when interpreting data