How to calculate force at constant velocity

F=m * a

"constant velocity" = zero acceleration

F=m * 0

F=0

This does not mean that there are no forces acting on your object, just no net force.

If this was homework, is was of the most basic type, and should not have posed a problem. If this is a real-life engineering question, I suggest you find another line of work.

Yeah, the force is zero in 'text book' world.

In the real world there is friction, air aerodynamic forces and sach like.
Easiest way is probably to measure it.
Del

'Text book' or real world, constant velocity means zero acceleration means no net force. Nothing more can be derived from the OP.

Unless he's talking about circular motion.

good answer,

but I know what he want to ask, for he dont know how to present his meaning with a correct description.

I know less english words, but most guys lack a good literary basic.

Your object (likely conveyor) - will need a force totally defined by the friction force that is being exerted on the supports (bearings), gears etc.

It is very difficult to say or guess the expected friction force and it is better to add them all up and then only go ahead with it.

As advised by Del _{(I normally don't agree with the quadrapeds with bows and arrows, boots OK)} The best way is to see it on action. However since this is your project work, () you have to calculate else you get a C^- in it.

Take all the moving and drive elements. calculate the efficiency of your gears (racks ?) bearings etc and with the required factr of safety calculate it.

Mind it (hopefully you know ) it is not only driving/maintaining your 18m/min. First it has to accelerate to it. At that time, (esp in your start) the static frictions come in play and not dynamic friction, and added to that the motor itself unfortunately give you less torque and draw more current.. However it will be momentary but may trip your relays and burn your fuse before you have even started the movement.

BTW: 50Kgs look to be too small a weight for conveyors along with oil sprayed sheet metals.

Dear friend,

Your conatant speed/velocity = 18m/m

Therefore the net constant force required = 18/60 x 50 kN

= 150 kN

Please add losses and convert in Kw for motors.

Thanks,

R S Sahni

why x50 KN ?

I reckon that your answer, the Force = 18/60/1m/s^2X50kg =15 N (1 N = 1 KgX1 m/s^2) but not 50Kn based on the assumption that the mass comes to rest within 1 sec. As righfully pointed out by others earlier, if the mass is having a constant speed then acceleraion is zero and hence the force is also zero.

Richard