How is the direction of an electric field defined?

Stion 13 of 20 : select the best answer for the question. 13. if a certain mass of mercury has a volume of 0.002 m3 at a temperature of 20°c, what will be the volume at 50°c? a. 0.002021624 m3 b. 0.004021624 m3 c. 0.000010812 m3 d. 0.002010812 m3

Which of the following changes will result in a stronger electromagnet? a. using fewer coils of wire b. using a higher voltage c. using a shorter nail d. using a longer wire

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.