Final answer:
It is false that grid references on a map are read from just the corner; full references come from both the Easting and Northing sides. Displacement is based on the overall change in position, not the path, and vector-related statements vary between true and false based on specifics of vector mathematics and physical principles.
Step-by-step explanation:
When reading a grid reference number corresponding to a grid on a map, it is false that you only read the pair of numbers corresponding to the corner of the square. Instead, you read the numbers along the sides of the grid square to get the full reference. For example, the Easting is read first followed by the Northing to give a full reference to a specific point within the square. As for the other questions regarding vectors and displacement:
- Displacement: It is false that the displacement of the first person will be more than the displacement of the second person if one walks 2 blocks east and 5 blocks north, and another walks 5 blocks north and then two blocks east, since displacement depends on the starting and ending point, not the path taken.
- Vector Components: It is true that a vector can form the shape of a right-angle triangle with its x and y components.
- Resultant Vector Angles: It is false that if only the angles of two vectors are known, we can find the angle of their resultant addition vector; you need the magnitudes as well.
- Pythagorean Theorem: It is true that we can use the Pythagorean theorem to calculate the length of the resultant vector obtained from the addition of two vectors which are at right angles to each other.
- The statement about the amplitude of waves is false; wave amplitudes can affect each other even when not perfectly aligned, due to the principle of superposition.
- Electric-field Lines: It is true that the electric-field lines from a positive point charge spread out radially and point outward.
- As for magnetic fields, it is true that it is not recommended to place credit cards with magnetic strips near permanent magnets.
With regards to latitude and longitude, these are indeed the coordinates used to specify any location on Earth with degrees north or south and east or west on the graticule.