how to calculate required torque?

please provide adequate information

I want to lift a 100 kgs by a DC motor, by converting rotary motion into reciprocating which lifts for a 150 mm upward distance, this coninues in operation.so to choose a suitable motor i need to calculate the torque required for same

calculate the tension on the wire rope- torque- shaft diameter- torque on motor.

Do your homework yourself. When you graduate are you going to run with these simple problems to your boss/collegue ?

Cheating here is not going be healthy for your career.

I suspect you are a student, but I'll give you some guidance nonetheless.

First, I assume you're trying to lift 100 kg. Note it is "kg", not "kgs". kgs is likely to be something altogether different.

The magnitude of torque is defined as rFsinØ. You will need to define those three quantities for us.

You will find that if you have enough torque to lift the weight 1 μm, you also have enough torque to lift it 1 km. Is there any possibility you meant to include time considerations and simply omitted that?

As TV mentioned, time is important. If you have an infinite amount of time, the HP required is very small. Take a look here and work out your answer

http://en.wikipedia.org/wiki/Horsepower

Dear Mr.HANUMANTHUGOLLA,

In your question, you have not mentioned the time or duration, through which the load is to be lifted. If the time is less the lifting speed will be high and hence power and TORQUE required will be high and vise-versa. Please indicate the time.

DHAYANANDHAN.S,

CR4 MEMBER.

Ohhhh boy, this is elementary Physics!!!!!

It's high time that you went back and opened up your textbook and studied it thoroughly.

Have a good day sir!