A2.00 meter long horizontal plank whose mass is 3.00 kg is placed so that the very end (the right end) rests on a retaining wall. the left end is put on the tailgate of the truck.
however the tailgate is tilted a bit, so it only contacts the board at a point 25.0 cm from the end. a 2.50 kg sledge hammer is placed 0.500 meters from the retaining wall.

a)find the force acting on the board by the tailgate.

b)find the force acting on the board by the retaining wall.

Explanation:

Given that:

From the image we can visualize the given situation.

Consider the given plank to be mass-less and having a uniformly distributed mass of 1.5 kg per meter.

Now in the balanced condition:

.......................(1)

...........................(2)

is the force acted by the tailgate on the plank.

Substitute the value from (2) into (1):

is the force acted by the wall upon the plank.

russian is not my first language, so i'm afraid i can't write out an answer in russian, but hopefully you can find a way to do so. here's my best translation of the problem: you're given a plot of a particle's position in one-dimensional space over time, and you're asked to find either the total distance traveled by the particle after 6 seconds had elapsed, or the total displacement of the particle after 6 seconds.

if you want the total distance traveled, you would first need to determine the particle's velocity as a function of time, then integrate that over the 6-second interval. we know the position function is quadratic with roots at 0 and 6, so we have

where is unknown. because the position is parabolic, there is symmetry about the midpoint at , and we know that

so that the position function is

which means the velocity is

then the total distance traveled is

so the total distance traveled is 20 m.

on the other hand, if you want to find displacement: the particle starts at and ends at , so its displacement is 0.

the maxium height is 34m/s