Answer:
152 N
Step-by-step explanation:
From the question,
F-F' = ma................. Equation 1
Where F = Horizontal force, F' = Frictional force, m = mass of the object, a = accleration of the object.
But,
F' = mgμ............... Equation 2
Where g = acceleration due to gravity, μ = coefficient of friction.
make m the subject of the equation
Substitute equation 2 into equation 1
F-mgμ = ma.
make m the subject of the equation
m = F/(gμ+a).............. Equation 3
Given: F = 125 N, g = 9.8 m/s², μ = 0.7, a = 1.2 m/s²
Substitute these value into equation 3
m = 125/[(9.8×0.7)+1.2)
m = 125/8.06
m = 15.51 kg.
But,
W = mg.............. Equation 4
Where W = weight of the object.
W = 15.51(9.8)
W = 152 N