What is meant by lenght

Need people build a dam to create a reservoir that supplies water a nearby city needs. describe two ways this action will likely affect the water cycle in the local environment. (5 points) worth 20 points

Ablue car pulls away from a red stop-light just after it has turned green with a constant acceleration of 0.5 m/s 2 . a green car arrives at the position of the stop-light 6.5 s after the light had turned green. if t = 0 when the light turns green, at what time does the green car catch the blue car if the green car maintains the slowest constant speed necessary to catch up to the blue car? answer in units of s.

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?