electrical engineering

Not enough data to give an answer.

Depending on the construction of the gate, it's area and windage may be more significant than it's weight .

Del

Hello you need to provide at least details as---

1 horizontal or vertical displacement.

2 amount of displacement.

3 Frictional coefficients of bearings.

4 Time to open gate.

5 linier or angular type motion.

mass = 2500kg, other parameters unknown (assumed).

To push up this mass, you need 2500kg x 9.8N/kg = 24500N

If you need to push up this mass for 3 meters, you need 24500N x 3 m = 73500J

If you need to work this in one minute, 73500 J : 60 sec = 1225W

1225W is absolute power to lift your gate to 3 meters in one minute.

The total efficiency is assumed as 0.3. So, you motor kW is 1225W : 0.3 = 4kW.

Hello,

As original post says 2500Kg is Weight ,So Gravitational acceleration of 9.8 already comes in picture, I mean weight of 2500KG is already equal to 2500KGF.

Second point is, since motions is horizontal, force required to push need to be multiplied by coefficient of friction.

Thanks and regards,

Your second point surely nullifies the first?
The gate isn't being lifted.
If friction can be minimised and time isn't an issue a few watts would do it!

Del

Yes,

Thats what my first post says too, just 42 watts are required if he wish to finish the task in one minute. and even the frictions coefficeinet is 0.5.

I revised my solution.

9.8kg/Newton is still required to convert kgf to Newton.

mass = 2500kg, Coefficient of friction is assumed as 0.5. Displacement is assumed as 2 meters.

To slide this mass, you need 2500kg x 0.5 = 1250kgf.

To convert kgf to Newton, 1250kgf x 9.8N/kgf = 12250N

you need to move this mass for 2 meters, you need 12250N x 2 m = 24500J

If you need to work this in one minute, 24500 J : 60 sec = 408W

408W is absolute power to move your gate to 2 meters in one minute.

The total efficiency including design margin is assumed as 0.3. So, your motor kW is 408W : 0.3 = 1361W.

So you need a 1.5kW or 2HP motor.

Regards

Yes you are right. gravity will to come in picture.

Now its perfect answer.

Sometime two wrongs make things right.

you can push it with even a little 3V DC motor out of a childs toy if speed is of no concern...