A person sees the image of an arrow reflected in a plane mirror. The dashed line in the figure represents the vertical center of the mirror. The person uses an opaque sheet to cover half of the mirror. A vertical mirror with the vertical center marked. The object is an upright arrow some distance in front of the upper half of the mirror. The base of the arrow is a small distance above the vertical center mark of the mirror. A face is in front of the lower half of the mirror and closer to the mirror than the arrow. The eye in the face is approximately the same distance below the vertical center of the mirror as the tip of the arrow is above the vertical center.
In which case will the person still see the image of the arrow?

A150 w lamp emits light of wavelength 590 nm uniformly in all directions. what is the photon flux (photons per unit area per unit time) on a small screen at a distance 2.3 m from the lamp? assume the photons are uniformly distributed over the surface of a sphere of radius 2.3 m.

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.

Why are graphs useful when interpreting data