(a). A particle, whose acceleration is constant, is moving in the negative x direction at a speed of 4.36 m/s, and 10.9 s later the particle is moving in the positive x direction at a speed of 7.94 m/s. Find the acceleration?(b). what will be the velocity 10.9 second before it was moving in the negative x directionat the speed of 4.36 m/s(c). when is the particle at rest. express this answer as a time in seconds elapsed since it was moving in the negative x-direction at a speed of 4.36 m/s.

Answer :

(a). Given data:

* The velocity of the particle in the negative x-direction is,

[tex]v_i=-4.36ms^{-1}[/tex]

* The velocity of the particle in the positive x-direction is,

[tex]v_f=7.94ms^{-1}[/tex]

* The time taken by the particle is,

[tex]t=10.9\text{ s}[/tex]

Solution:

The acceleration in terms of velocity and time is,

[tex]a=\frac{v_f-v_i}{t}[/tex]

Substituting the known values,

[tex]\begin{gathered} a=\frac{7.94-(-4.36)}{10.9} \\ a=\frac{7.94+4.36}{10.9} \\ a=1.128ms^{-2} \end{gathered}[/tex]

Thus, the acceleration of the particle is 1.128 meter per second squared.

(b). The velocity before the 10.9 second of the -4.36 m/s velocity is,

[tex]\begin{gathered} a=\frac{v_f-v}{t} \\ 1.128=\frac{-4.36-v_{}}{10.9} \\ 12.295=-4.36-v \\ -v=12.295+4.36 \\ -v=16.655 \\ v=-16.655ms^{-1} \end{gathered}[/tex]

Thus, the value of the velocity is -16.655 meter per second.

(c). Let at time t particle will come to rest,

The time t in terms of acceleration is,

[tex]\begin{gathered} a=\frac{v_f-v_i}{t} \\ 1.128=\frac{0-(-4.36)_{}}{t} \\ t=\frac{4.36}{1.128} \\ t=3.865\text{ s} \end{gathered}[/tex]

Thus, the particle will come to rest after 3.865 s since the velocity 4.36 m/s in negative x-axis.