Show all of your work for the following questions and circle your answer! (4 points) The driver of a 9800 N car is cruising along at 35 m/s and removes her foot from the gas pedal
for 7s when her speed is then 30 m/s. What force of friction caused her car to slow down during that
time. Draw and completely label a free-body diagram for full credit.
(4 points) A 300 N wagon (with a child in it) are being pulled from rest. They are pulled with 40 N of force
against 25 N of friction. After being pulled for 5 s, how fast is the wagon & child combo now moving?
Draw and completely label a free-body diagram for full credit.

i don't know that i agree with that but what's the question ?

cant without the picture! ?

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.