You take the opportunity to stock up on snacks and head on your way. You wind al

Question

You take the opportunity to stock up on snacks and head on your way. You wind along the road for quite some time before you nd a very dark site and pull of onto dirt road. About 100 meters up the road your passage is stopped by a metal gate. The gate consists of a single heavy bar stretching 6 meters across the road. It looks like schedule 5 stainless steel pipe, of all things, clocking in at about 7 kg/linear meter if you recall correctly. It is hinged on the left side allowing you to lift it upwards. You know from experience that you can lift about 20 kg without much effort. Where should you lift the gate to apply the proper torque to move the bar?

Explanation / Answer

I need to balance the torque of weight of the bar about its other end (left end)

wt. of bar can be assumed to be concentrated at its middle point (which is center of mass of the uniform bar)

thus point of application of wt. is 6/2 m right to left end

so torque of wt. of bar = (7*6) *3 kg wt.meter = 126 kg wt.meter

capacity of lifting = 20 kg (without much effort)

so to balance the torque of weight i should apply that force at a distance x = 126/20 meter from left end = 6.3 meter right from left end

Related Questions

Navigate

• Browse (All)
• Browse Y
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.