Answered

A box of mass 4.5kg is pushed horizontally to the right across a level floor with a force of 12.0N. There is also a kinetic friction force of 3.5N. A) Find the net force and the rate of acceleration of the box.



Answer :

belali

A) The direction of the friction force vector must be opposite to the direction of motion.

Since there is movement in the horizontal direction, we subtract the magnitude of the friction force from the force we apply;

  • [tex]F_{net}=12N-3.5N=8.5N[/tex]

B) To find the rate of acceleration of the box, we need to use Newton's [tex]2^{nd}[/tex] Law.

  • [tex]F_{net}=m_{box}\times a_{box}[/tex]
  • [tex]8.5N=4.5kg\times a_{box}[/tex]

Hence;

  • [tex]a_{box}=\frac{8.5N}{4.5kg}[/tex]
  • [tex]a_{box}=\frac{17}{9}\times (m/s^2)[/tex]

Summary:

A) [tex]F_{net}=8.5N[/tex]

B) [tex]a_{box}=\frac{17}{9}\times (m/s^2)[/tex]