Question

A 5.0-kg bag of groceries is tossed onto a table at 2.0 m/s and slides to a stop in 1.6 s .

Answer 1

Answer:

-6.3 N

Explanation:

The equation we need to use is:

$F \Delta t = \Delta (mv)$

where

F is the force of friction, that slows down the bag

$\Delta t$ is the time of the motion

m is the mass of the bag

v is the speed of the bag

Since the mass of the bag does not change, we can rewrite the equation as

$F \Delta t= m \Delta v$

where we have:

$\Delta t=1.6 s\\m=5.0 kg\\\Delta v=-2.0 m/s$

Substituting and re-arranging the equation, we can find the force of friction:

$F=\frac{m\Delta v}{\Delta t}=\frac{(5.0 kg)(-2.0 m/s)}{1.6 s}=-6.3 N$

where the negative sign means that the force is in the opposite direction to the motion of the bag.