Grade 11Mechanics
4. One end of a string of length l is connected to a particle of mass m and the other to a small peg on a smooth horizontal table. If the particle moves in a circle with speed v the net force on the particle (directed towards the centre) is:
(i) T, (ii) T-mv²/r, (iii)T+mv²/r, (iv) 0
T is the tension in the string. [Choose the correct alternative].
Ans. (i) When a particle connected to a string revolves in a circular path around a centre, the centripetal force is provided by the tension produced in the string. Hence, in the given case, the net force on the particle is the tension T, i.e.,
F = T = mv²/r
Where F is the net force acting on the particle.
my question is that why the net force is not zero considering centriugal force(mv²/r) in outward direction being balanced by centripetal force(=tension=-mv²/r) in inward direction
4. One end of a string of length l is connected to a particle of mass m and the other to a small peg on a smooth horizontal table. If the particle moves in a circle with speed v the net force on the particle (directed towards the centre) is:
(i) T, (ii) T-mv²/r, (iii)T+mv²/r, (iv) 0
T is the tension in the string. [Choose the correct alternative].
Ans. (i) When a particle connected to a string revolves in a circular path around a centre, the centripetal force is provided by the tension produced in the string. Hence, in the given case, the net force on the particle is the tension T, i.e.,
F = T = mv²/r
Where F is the net force acting on the particle.
my question is that why the net force is not zero considering centriugal force(mv²/r) in outward direction being balanced by centripetal force(=tension=-mv²/r) in inward direction
