Answer: 1327 kg
Explanation:
First of all, we can notice that the forces along the vertical direction (gravity and normal force) are equal and opposite, so they cancel each other and we can ignore them.
The relationship between the net force on the horizontal direction and the acceleration of the wagon is given by Newton's second law:
[tex]\sum F = ma[/tex]
where
[tex]\sum F[/tex] is the net force on the wagon
m is the mass of the wagon
a is the acceleration
In this problem, the net force on the wagon is:
[tex]\sum F=1,000 N+800 N-75 N=1,725 N[/tex]
the mass is unkown
and the acceleration is [tex]a=1.3 m/s^2[/tex]
So we can re-arrange the equation above to find the mass of the wagon:
[tex]m=\frac{\sum F}{a}=\frac{1725 N}{1.3 m/s^2}=1327 kg[/tex]
