A boat starts moving across a river at velocity v perpendicular to the river bank. The boat encounters a current along the river of velocity u, as shown.
u
river
Which vector diagram shows the resultant velocity r of the boat?
A
B
с
D
u
A
r
u

Sawyer is studying diffraction. he draws a diagram of a plane wave to show how light waves travel. which best describes sawyer’s error? the wave fronts should be perpendicular to the direction in which the waves move. the arrow showing the direction of movement of the waves should be pointing to the left. the arrow showing the direction of movement of the waves should be pointing downward. the wave fronts should be both parallel and perpendicular to the direction in which the waves move.

1. how to locate the image in converging(concave) mirror and diverging (convex) mirror with salt. 2. how to locate the image in a converging (convex) lens and diverging (concave) lens with salt.

In a good thermo flask the main cause of heat loss is