Question

Ma ajutati va rog.Multumesc anticipat

Answer 1

4.
a)OA-modulul vitezei initiale a mobilului 3
OB-modulul vitezii initiale a mobilului 2
OC-modulul vitezii finale a mobilului 3

b)a=Δv/Δt=(v-v0)/t, Δt e in general t-t0, dar in grafie t0=0 pentru toti

Din grafic:

Primul corp:

v01=0m/s
v1=10m/s
t=6s

a=$\displaystyle \frac{0-10}{6}=-\frac 53$ m/s²

Al doilea corp:

v02=3m/s
v2=10m/s
t2=6s

a=$\displaystyle \frac{10-3}{6}=\frac 76$ m/s²²

Al treielea corp:

v03=10m/s
v3=0m/s
t=10s

a=$\displaystyle \frac {10-0}{10}=1$ m/s²

c)v(t)=v0+a*t
d(t)=v0*t+at²/2

Inlocuim v0 si a pentru cele trei corpuri:

1)v1(t)=$\displaystyle -\frac 53t$ m/s
d1(t)=$\displaystyle -\frac {5t^2}6$

2)v2(t)=$\displaystyle 3+\frac 76t$
d2(t)=$\displaystyle 3t+\frac{7t^2}{12}$

3)v3(t)=$\displaystyle 10+t$
d3(t)=$\displaystyle 10t+\frac{t^2}{2}$


5.
[tex]\displaystyle \text{Se da:}\\ \\ t=15s\\ \\ v=100\frac ms\\ \\ a=\frac m{s^2}\\ \\ d=?m\\ \\ \\ Formule:\\ \\ a=\frac vt\\ \\ \\ d=\frac {v\times t}2\\ \\ \\ Calcule:\\ \\ a=\frac{100}{15}\approx 6,67\frac m{s^2}\\ \\ d=\frac{100\times 15}{2}=750m[/tex]


6.
[tex]\displaystyle \text{Se da:}\\ \\ v_0=1000\frac ms\\ \\ t=0,001s\\ \\ v=200\frac ms\\ \\ d=?m\\ \\ \\ Formule:\\ \\ d=\frac{v+v_0}{2}\times t\\ \\ \\ Calcule:\\ \\ d=\frac{1000+200}{2}\times 0,001=0,6m[/tex]