Please teach the physical displacement difference is a few chapters and sections Thank you.

1. The speed between AB is 2 meters per second.

The velocity between BC is the meter per second subtracted by the time.

2. The instantaneous velocity leakage of point B: , divided by time, because the distance of 5 points is a counting point, so the time between AB is also argued as the AC distance divided by the time between AC.

So time is all about meters per second!! Acceleration, , wood high rock to find out. Yes.

The third question. <>

t=s v=180 5=36 (sec).

When the current velocity is v1 = 6 m s, the boat is still not 5 m s relative to the hydrostatic speed (the figure is longer). The increase in the speed of the current only increases the speed of the boat to drift downstream, so that the boat reaches the opposite shore away from the target point on the opposite shore.

The minimum displacement of the boat when it reaches the opposite bank: it is the width of the river 180 meters. The vertical distance between the two shores is the shortest, regardless of the angle between the bow and the direction perpendicular to the opposite bank, the ship arrives at the opposite shore and is exactly opposite the starting point, which is the minimum displacement.

The V in the diagram is longer.

Relative displacement = belt to position shift vt - mail to position shift (easy to calculate = vt 2) = vt 2;t is the relative sliding time of the mail on the belt. It's easy to see in a schematic diagram: the mail moves to the left relative to the belt.

The ants crawl along the AKG for the shortest distance, and the positive guess cube is in the form of the right figure, and the minimum distance of the sedan is obtained = gh +ah ) a +(2a) ] closed back 5 years

The displacement is equal to the diagonal ag of the cube , ag = ae +ge ) ae +gh +he ) a +a +a ) 3 a

If the displacement difference is different, the most "displacement segments" are selected to find the approximate value.

The acceleration of a in the oblique part is the same as that of b, because the two lines are parallel, and the slope indicates the speed of the gadan ruler, so the slope is the same and the acceleration is the same.

Forty seconds ago, A's velocity was greater, and if they were in the same place and moving in the same direction, A would start first, and start first, so the distance between them was increasing (which can be understood as B chasing A, but B's speed was slow, so they were getting farther and farther apart), and after forty seconds, B's velocity was greater than A's, so the distance between them began to decrease, and at forty seconds the distance between them reached its maximum. The distance between them is the area of the pentagon enclosed by the two curves and the x-axis and y-axis.