Question

A 12-kg bag of groceries is tossed onto a table at 4.0 m/s and slides to a stop in 2.2 s .
Modify the equation FΔt=Δ (mv) to find the force of friction.

Answer 1

As we know that bag is stopped due to the force of friction on the table

so here by the given equation we will say

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

now we have

$F = \frac{\Delta (mv)}{\Delta t}$

now from the above equation we also have

$F = \frac{(mv)_f - (mv)_i}{\Delta t}$

now we have

$v_f = 0$

$v_i = 4 m/s$

m = 12 kg

$\Delta t = 2.2 s$

now we will have

$F = \frac{0 - (12)(4)}{2.2}$

$F = -21.82 N$

so friction force will be 21.82 N