What is the acceleration of a sled in a tractor-pull competition?

[Enduro]

Homework Statement

In a tractor-pull competition, a tractor
applies a force of 1.3 kN to the sled, which
has mass 1.1 × 104 kg. At that point, the coefficient
of kinetic friction between the sled
and the ground has increased to 0.80. What
is the acceleration of the sled? Explain the
significance of the sign of the acceleration.


f=1300n
m = 1.1 x 10^4 kg
m =0.80
a=?

Homework Equations

F=ma

m=Ff/Fn

Fnet= Fx+Fy

The Attempt at a Solution

ff=0.80 x (9.8)(1.1x10^4)
ff= 86240


86240=(1.1 x 10^4kg) a

a= 7.85m/s2

 

[siddharth23]

There are two forces acting on the sled here. One is by the tractor, the other is due to friction. By Newton's second law of motion, the NET force is equal to the product of mass and acceleration.
Fnet = ma.

You've considered only ff in calculating the acceleration.

Also, make sure if you've taken the weight correctly. An 11 ton sled seems like a lot!