Answer: 1.55 m
Explanation:
from the question we were given
force = 125 N
distance = 1 m
mass = 20 kg
first we find the work done in pushing her = force x distance
work done = 125 x 1 = 125 j
now we find the frictional force = ( coefficient of friction x mass x acceleration due to gravity ), taking the coefficient of friction as o.25 and acceleration due to gravity as 9.8 m/s
frictional force = 0.25 x 20 x 9.8 = 49 N
the frictional force must do the same amount of work Zak did in pushing his sister so as to bring her to a stop. now we can get the distance she slides by applying the formula work done = frictional force x distance
125 = 49 x distance
distance = 125 / 45 = 2.55 m
to get how far she slides after Zak's push stops we have to subtract the distance she was pushed for from the total distance she slid
= 2.55 - 1 = 1.55 m