The torque is the component of the weight that is perpendicular to the bar. So when the bar hangs vertically down, parallel to the force of gravity, there is no torque. If the bar makes an angle "A" with the vertical then the component of weight perpendicular to the bar would be mgSin(A) and the torque would be mgLSin(A) , where m= 1.21 kg, and L = 1.28m, g=9.8m/ss , so all you need is the angle "A".
Because at infinite speed, it's mass will become zero, which is not possible as it consists of photons which are not massless particles.
The question says nothing about the motion of the pendulum, or about its position at the instant we're supposed to consider, only that it "hangs". If it's just hanging there limp, then the force is acting straight through the pivot, the distance between the line of the force and the pivot is zero, so the torque = R x F is zero.================================================= Did the question mean to say that the 1.28 m is the horizontaldistance between the pivot and the vertical, on account of the bar is slanted ??? If that's the case, why then the vertical force due to gravity is the weight of the bob = m x g = 1.21 x 9.8 = 11.858 N. The magnitude of the torque = |R x F| = 1.28 x 11.858 = 15.178 Newton-Meters.
Yes. The gauge particles for the electromagnetic force are (massless) photons, so there's no distance limit to electromagnetic interactions.
Quantisation of electric Field consists of discrete energy parcels, photons. Photons are massless particles of definite energy, definite momentum, and definite spin.
This is a much more complicated question than can be answered with a simple True or False.
photonsgravitonsBoth are bosons, there are no massless fermions although neutrinos were once believed to be massless.
One method is to determine the effectivity of the electromagnetic force over a distance. The electromagnetic force acts over an infinite distance and therefore the photon, the particle that mediates the electromagnetic force, is massless.
Yes
Zero.
I think that it is impossible for a massless body to move an electron from its path. Photons are massless but how they are able to displace an electron having mass.
No. A photon is a particle of light. It is massless.
photons