A particle initially located at the origin has an acceleration of a 2.00j m/s2 and an initial velocity of v-6.00i m/s. (a) Find the vector position of the particle at any time t (where t is measured in seconds). ti+ t2 j) m (b) Find the velocity of the particle at any time t. I + tj) m/s (c) Find the coordinates of the particle at t 5.00 s. (d) Find the speed of the particle at t 5.00 s. m/s

Respuesta :

Answer:

  • [tex]\vec{r}(t) = (-6.00 \frac{m}{s} \ t , \frac{1}{2} \ 2.00  \ \frac{m}{s^2} \ t^2 )[/tex]
  • [tex]\vec{v}(t) = (-6.00 \frac{m}{s}, 2.00  \ \frac{m}{s^2} \ t )[/tex]
  • [tex]\vec{r}( 5.00 \ s) = (-30.00 \ m , 25.00 \ m )[/tex]
  • [tex]| \vec{v} (5.00 \ s) | =11.66 \frac{m}{s}[/tex]

Explanation:

The initial position of the particle, [tex]\vec{r}_0[/tex], is:

[tex]\vec{r}_0 = (0,0)[/tex]

the initial velocity is:

[tex]\vec{v}_0 = - 6.00 \ \frac{m}{s} \hat{i} = (-6.00 \frac{m}{s},0)[/tex]

and the initial acceleration:

[tex]\vec{a} = 2.00  \ \frac{m}{s^2} \ \hat{j} = ( 0, 2.00  \ \frac{m}{s^2})[/tex]

a

The position [tex]\vec{r}[/tex] at time t is

[tex]\vec{r}(t) = \vec{r}_0 + \vec{v}_0  \ t   + \frac{1}{2} \ \vec{a} \ t^2[/tex]

So, for our problem is:

[tex]\vec{r}(t) = (0,0) + (-6.00 \frac{m}{s},0)  \ t   + \frac{1}{2} \ ( 0, 2.00  \ \frac{m}{s^2}) \ t^2[/tex]

[tex]\vec{r}(t) = (0 -6.00 \frac{m}{s} \ t , 0 +  \frac{1}{2} \ 2.00  \ \frac{m}{s^2} \ t^2 )[/tex]

[tex]\vec{r}(t) = (-6.00 \frac{m}{s} \ t , \frac{1}{2} \ 2.00  \ \frac{m}{s^2} \ t^2 )[/tex]

b

The velocity [tex]\vec{v}[/tex] at time t is

[tex]\vec{v}(t) = \vec{v}_0  + \vec{a} \ t[/tex]

So, for our problem is:

[tex]\vec{v}(t) = (-6.00 \frac{m}{s},0)   + ( 0, 2.00  \ \frac{m}{s^2}) \ t[/tex]

[tex]\vec{v}(t) = (-6.00 \frac{m}{s}, 2.00  \ \frac{m}{s^2} \ t )[/tex]

c

At time 5.00 seconds the position will be:

[tex]\vec{r}( 5.00 \ s) = (-6.00 \frac{m}{s} \ 5.00 \ s , \frac{1}{2} \ 2.00  \ \frac{m}{s^2} \ (5.00 \ s ) ^2 )[/tex]

[tex]\vec{r}( 5.00 \ s) = (-30.00 \ m , 25.00 \ m )[/tex]

d

and the speed will be :

[tex]| \vec{v} (5.00 \ s) | = |(-6.00 \frac{m}{s}, 2.00  \ \frac{m}{s^2} \ 5.00 \ s) |[/tex]

[tex]| \vec{v} (5.00 \ s) | = |(-6.00 \frac{m}{s}, 10.00  \ \frac{m}{s}) |[/tex]

[tex]| \vec{v} (5.00 \ s) | = \sqrt{ (-6.00 \frac{m}{s})^2 + (10.00  \ \frac{m}{s}))^2 }[/tex]

[tex]| \vec{v} (5.00 \ s) | = \sqrt{ 36.00 \frac{m^2}{s^2} + 100.00  \ \frac{m^2}{s^2}}[/tex]

[tex]| \vec{v} (5.00 \ s) | =11.66 \frac{m}{s}[/tex]