# physics

posted by bharat narke

a uniform bar of mass is supported by support pivoted at top about which bar can swing like simple pendulum. If force F is applied perpendicular to lower end of the bar.How big F must be in order to held the bar in equilibrium.

1. drwls

That will depend upon the angle A that the bar makes with the vertial axis.
The torque due to the weight of the bar, measuered about the pivot, but equal the applied torwue, F*L

F*L = M*g*sin A*(L/2)

(L/2 is the distance of the center of m,ass from the pivot).

Solve for F. L cancels out

F = (M g sinA)/2

## Similar Questions

1. ### Physics

A 60-cm-long, 500 g bar rotates in a horizontal plane on an axle that passes through the center of the bar. Compressed air is fed in through the axle, passes through a small hole down the length of the bar, and escapes as air jets …
2. ### Physics

A uniform bar of iron is supported by a lon, uniform Hooke's Law spring. The spring is cut in half exactly and the two pieces are used to support the same bar. If the whole spring is stretched by 4 cm in the first bar (that is not …
3. ### Mechanics _ physics

A uniform bar 1m long is pivoted at the centre has a mass of 3kg. It is acted upon by a conquer which cause to possess an angular acceleration of 6rad/sec^2; calculate a. The moment of inertia of the bar b. The torque on the bar
4. ### physics

bar subjected to gravity load (two segments) the bar in the fig has constant cross sectional area A .the top half of the bar is made of material with mass density and youngs module, the bottom half of the bar made of density and young …
5. ### physics

bar subjected to gravity load (two segments) the bar in the fig has constant cross sectional area A .the top half of the bar is made of material with mass density and youngs module, the bottom half of the bar made of density and young …
6. ### physics

bar subjected to gravity load (two segments) the bar in the fig has constant cross sectional area A .the top half of the bar is made of material with mass density and youngs module, the bottom half of the bar made of density and young …
7. ### Physics

A uniform bar length of 2.0m and weight 1000 N has its center of gravity at its center. The bar is pivoted 0.5m from the right, and supports a weight of 200N on the opposite end (left end). What is the weight needed at right end of …
8. ### physics

Help: A 2 meter long, uniform bar with a mass of 46 kg is suspended from a pin so it can rotate freely. It is supported by a cable half a meter from the end. Find the tension force in the cable and the magnitude and direction of the …
9. ### Physics

A small 0.13 g bug stands at one end of a thin uniform bar that is initially at rest on a smooth horizontal table. The other end of the bar pivots about a nail driven into the table and can rotate freely, without friction. The bar …
10. ### Physics

The figure (Figure 1) shows a model of a crane that may be mounted on a truck.A rigid uniform horizontal bar of mass m1 = 80.0 kg and length L = 5.30 m is supported by two vertical massless strings. String A is attached at a distance …

More Similar Questions