SOLUTION: 1) A tractor applies a force of 1300N to the sled,which has mass of 11000kg. At that point the coefficient of friction increased to 0.80. what is the acceleration of the sled? and

Algebra ->  Human-and-algebraic-language -> SOLUTION: 1) A tractor applies a force of 1300N to the sled,which has mass of 11000kg. At that point the coefficient of friction increased to 0.80. what is the acceleration of the sled? and      Log On


   

Question 308025: 1) A tractor applies a force of 1300N to the sled,which has mass of 11000kg.
At that point the coefficient of friction increased to 0.80. what is the acceleration of the sled? and explain the significant of the sign.
Thanks.
James.
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Not really an algebra problem but here's how it's done.
The sum of the forces equals mass multiplied by acceleration.
I'm assuming the force applied by the tractor (T) is perpendicular to the weight of the sled (W=mg). The forces acting are the weight in the y direction (up-down) and an equal and opposite force from the floor so that y acceleration is zero.
Friction acts in the direction to oppose movement (opposite the tractor pull force) and is equal to the product of the weight (W) and friction coefficent (mu).
F=ma=T-mu%2AW
a=%28T-mu%2Amg%29%2Fm=%281300-%280.8%2911000%289.8%29%29%2F11000
Since the friction force is greater than the force applied by the tractor, the sled does not move.
The tractor has to apply a force at least greater than mu%2Amg=86240 N to accelerate the sled. Any force less than that will not move the sled.
a=0