Hi,
The question im a bit confused about is this:

A block is dragged across the ground by a light cable,attached to a winch. Th block is initally at rest.

Information given:
Volume: 6m³
Density 2875 kg/m³
Coefficent of friction between block and the ground: 0.4
Diameter of winch: 1.4m

Find the force that must be applied to the block to overcome friction and cause it to accelerate at a rate of 0.4m/s²


So I've first got to find the mass right? m=D.V= 2875*6= 17,250 KG

Then I can find its weight. w=m.g = 17,250*9.81= 169,222.5 N

Now I need to find the force acting down on the block right? Fa= m.a
=17,250*0.4= 6900N

And the frictional force acting Frictionalforce= μ*w = 0.4*169,222.5= 67,689N

Then the total force should equal: Tforce=√Frictional force²+Fa²= √67689²+6900²= 68,039.77308 right?

Have I gone wrong somewhere?

Many thanks
Matt