Along cylindrical shell (radius = 2.0 cm) has a charge uniformly distributed on its surface. if the magnitude of the electric field at a point 8.0 cm radially outward from the axis of the shell is 85 n/c, how much charge is distributed on a 2.0-m length of the charged cylindrical surface? the answer is suppose to be 0.76nc, i just don't know how to get there. explain

Askydiver weighing 140 lb (including equipment) falls vertically downward from an altitude of 19,000 ft and opens the parachute after 18 s of free fall. assume that the force of air resistance, which is directed opposite to the velocity, is of magnitude 0.55|v| when the parachute is closed and is of magnitude 14|v| when the parachute is open, where the velocity v is measured in ft/s. assume that acceleration due to gravity has magnitude 32 ft/s/s; remember that weight is the product of mass and gravitational acceleration. (a) find the speed of the skydiver when the parachute opens. (b) find the distance fallen before the parachute opens. (c) what is the limiting velocity vl after the parachute opens? (d) determine how long the sky diver is in the air after the parachute opens. (e) plot the graph of velocity versus time from the beginning of the fall until the skydiver reaches the ground.

What is the scientific definition of energy that relates to work

Which pair of quantities includes one quantity that increases as the other decreases during simple harmonic motion?