To solve this problem we will use the concepts related to the Impulse-Momentum Theorem for which it is specified as the product between force and change in time
[tex]\Delta p = F\Delta t[/tex]
And
\Delta p = m\Delta v
Where,
[tex]F = Force[/tex]
[tex]\Delta t = \text{Change in Time}[/tex]
[tex]\Delta v = \text{Change in velocity}[/tex]
[tex]m = mass[/tex]
Rearranging to find the Force we have that
[tex]F = \frac{\Delta p}{\Delta t}[/tex]
Using the expression between mass and velocity
[tex]F = \frac{m(v_f-v_i)}{\Delta t}[/tex]
Our values are given as,
[tex]m = 50.2kg\\v_i = 0m/s \\v_f = 2.8m/s \\\Delta t = 20.1s[/tex]
Then replacing we have that
[tex]F = 6.99N[/tex]
Therefore the average force is 6.99N
