* At the famous Military Science Institute X, set up by five leaders of the world's most powerful groups, they discuss future tasks on climate change, along with Dr Adam, whose grandson of the party chairman has said There were “secret mysteries behind the disaster.” He went on to say that countries with civilization and culture still had icons related to light at the time his research team conducted research for 10 years. And they also collected the clock-shaped keys, carved from when the earth would be catastrophic if it wasn't locked according to the rules the ancients used to do. At this meeting, many people expressed their displeasure and disbelief with what young Dr Adam said because he only wanted to continue to exploit the natural resources and did not want to spend money on funds from environmental protection. But when the screen jumps, showing a huge volcanic eruption at the same time as sea level rise, the warning signal….
Vector Addition and Subtraction Suppose a particle undergoes a displacement followed by a second displacement . The final result is the same as if the particle had started at the same initial point and undergone a single displacement (Fig. 1.11a). We call displacement the vector sum, or resultant, of displacements and We express this relationship symbolically as (1.2) The boldface plus sign emphasizes that adding two vector quantities requires a geometrical process and is not the same operation as adding two scalar quantities such as In vector addition we usually place the tail of the second vector at the head, or tip, of the first vector (Fig. 1.11a). If we make the displacements and in reverse order, with first and second, the result is the same (Fig. 1.11b). Thus (1.3) This shows that the order of terms in a vector sum doesn’t matter. In other words, vector addition obeys the commutative law. Figure 1.11c shows another way to represent the vector sum: If vectors and are both drawn with their tails at the same point, vector is the diagonal of a parallelogram constructed with and as two adjacent sides. CAUTION Magnitudes in vector addition It’s a common error to conclude that if