Relation between velocity and force

[animespt]

Ok, so here's the question. To make a car move, we need a force, however, the velocity of the car is related to force? By example, we made a force to make the car start moving and the car started moving with a velocity of 10m/s. Then later the car has a velocity of 20m/s. So, the increase of the velocity is caused by a bigger force pushing the car? Cos, i do know that if the car is moving, then it has the tendence to keep moving with a constant velocity, it can only be stopped with a force in the opposite way to make it stop, so to make it go faster, then there's a force pushing it to go faster?

 

[Hootenanny]

Welcome to Physics Forums.

I'm not sure that I entirely understand your question, but yes, to change an body's velocity there must be a net force acting on that body.

 

[animespt]

ok, and what's the formula to find the force used in the increase of velocity? thanks by the answer gived by the way.

 

[ZapperZ]

Er... F=ma!

Zz.

 

[animespt]

but that's when a = v^2/r in a circular movement. and on a rectilineous movement?

 

[Hootenanny]

but that's when a = v^2/r in a circular movement. and on a rectilineous movement?

Newton's second law can be applied to any classical motion, when rectilinear or curvilinear.

I just want to make sure that you know that the equation for acceleration that you quoted is only valid for circular motion.

 

[ZapperZ]

but that's when a = v^2/r in a circular movement. and on a rectilineous movement?

What?

Since when is F=ma only valid in circular motion?

Zz.

 

[russ_watters]

I also want to make sure you understand how Newton's first law applies to a car: the car decelerates when you take your foot off the gas pedal because there are forces acting to decelerate it. And when you add more gas, the car accelerates to a new equilbrium with its opposing forces. Force has no direct relationship with velocity, only acceleration.