When two people swing a jump rope, they can make it swing as a single arc or as two half-ropes arcing in opposite directions?

Sort the images based on whether there's a force of attraction or repulsion between the magnets shown. attraction repulsion

Aspring with an unstrained length of 0.071 m and a spring constant of 2.6 n/m hangs vertically downward from the ceiling. a uniform electric field directed vertically upward fills the region containing the spring. a sphere with a mass of 5.29 10-3 kg and a net charge of +7.2 µc is attached to the lower end of the spring. the spring is released slowly, until it reaches equilibrium. the equilibrium length of the spring is 0.058 m. what is the magnitude of the external electric field?

Which type of heating system is used to heat many buildings from a central location?