# Why is work scalar and the dot product of force and displacement?

I asked many people why work is scalar. But the questions and the answers just cycles.

My question : Why is work a scalar quantity?

Their answer : Because it is the dot product of Force and Displacement. So it is a scalar quantity.

My question : Why is work the dot product of force and displacement and not the cross product?

Their answer : Because it is a scalar quantity and not a vector.

So can anyone please tell me why work is scalar apart from this cycle of questions and answers? Is there any other logic which can answer both questions?

Edit : $W=Fs\cos\theta$. So $Fs\cos0 = -Fs\cos180$. So shouldn't work be a vector? This confusess me.

• If you are happy with my answer, you can accept it. Otherwise let me know in a comment under my answer if you still have doubts and I can address them. – Andrea Aug 1 '18 at 11:10