A jogger takes 30 s to run a total distance of 200 m by running 150 m [E] and then 50 m [W]. (a) Calculate the jogger’s average speed (b) Calculate the jogger’s average velocity

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?