Answer:
The answer is 0.39 m/s ²
Explanation:
Since the box moves with steady speed,
Friction=force in even direction=260*Cos20=244.3N
Ordinary force=mg+FSinθ=1089N
μN=f
μ=244.3/1089=0.224
N=mg-FSinθ=911.1N
a=(260 Cos20-0.224*911.1)/(1000/9.8)=0.39m/s²