Two particles, 1 and 2 moves with constant velocities v1 and v2. At the initial moment their radius vectors are equal to r1 and r2. How must these four vectors be interrelated for the particles to collide. Solution: Let the particles collide at the point A (Fig.) whose position vector is  ( {{vec{r}}_{3}} ) (say).…

A point moves rectilinearly in one direction. Fig. 1.1 shows the distance s traversed by the point as a function of the time Using the plot find: (a) the average velocity of the point during the time of motion; (b) the maximum velocity; (c) the time moment t0 at which the instantaneous velocity is equal…

A car starts moving rectilinearly, first with acceleration w = 5.0 ms-2 (the initial velocity is equal to zero), then uniformly, and finally, decelerating at the same rate w, comes to a stop. The total time of motion equals τ = 25 s. The average velocity during that time is equal to v = 72…

A point traversed half the distance with a velocity v0. The remaining part of the distance was covered with velocity v1 for half the time, and with velocity v2 for the other half of the time. Find the mean velocity of the point averaged over the whole time of motion. Solution: Let s be the…

A motorboat going downstream overcame a raft at a point A;  ( tau =60,,min )  later it turned back and after some time passed the raft at a distance  ( ell =6.0,,km )from the point Find the flow velocity assuming the duty of the engine to be constant. Solution: Let v0 be the stream velocity…