Solenoid (a) has twice the diameter, there time the length, and four times the number of turns of solenoid (b).

What is the electric force acting between two charges of -0.0045 c and -0.0025 c that are 0.0060 m apart? use fe=kq1q2/r^2 and k = 9.00 x 10^9 n*m^2/c^2 a. 1.7 x 10^7 n b. -1.7 x 10^7 n c. -2.8 x 10^9 n d. 2.8 x 10^9 n

Which accurately compares concave and convex lenses?

What’s #16 asking and how do i solve it?