Net force on a Merecedes convertible

[92EG6]

this is really into stuff and i fell really dumb that i can't figure this stuff out...

What is the net force on a Merecedes convertible traveling along a straight road at a steady speed of 110 km/hr? Answer in N
Where do i start?

If it takes 1 N to push horizontally on your book to make it slide at a constant velocity, how much force of friction acts on the book? Answer in N
If the book keeps moving at that constant speed i figured that i would be 0 but i was wrong... what am i doing wrong?

Three identical blocks are pulled on a horizontal frictionless surface. If tension in the rope held by the hand is T = 60 N, what is the tension in the other ropes?
Where do i start?

Thanks

 

[H_man]

The engine is generating a force which is making the car move forward. When you are traveling at a constant speed in your car it means that the drag forces are equal to the force generated by the engine.

In short, just like with the book the forces in one direction are balanced by the forces in the other. This is why the book moves at constant speed! The forces are balanced.

Something will only change its speed or velocity if there is a NET or overall force.

I strongly recommend you read Newtons Laws. In particular the first! This will explain this and much more.

 

[92EG6]

thanks that helped