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Impulsive Tension in Strings

Three masses A, B and C of 2, 1 and 3 kg respectively lie on a smooth horizontal table with angle ABC = 30°. Light inextensible strings connect A to B and B to C, with the strings just taut. A horizontal impulse of 5 Ns is applied to B in the direction of AB.

Set up the equations to find the initial speeds of the masses. Hence verify (by substitution, or otherwise) that these speeds are: 7/6 m/s for A, (root 19)/3 m/s for B and 1/(root 3) m/s for C. (50%)

I can normally do these type of questions, but for some reason, i can't manage to get the correct answer here. I'm wondering whether there is a mistake with the answers it wants me to achieve?

Reply 1

Fermat

The answers are correct.

I'm not sure if this is what you wanted, since I found it simpler to just solve directly for the speeds, rather than derive individual expressions for them, then verify/find the speeds.

Anyway, hope this helps.

Any problems with the working/handwriting/... please post back.

N.B. I use horizontal and vertical simply to represent two mutually orthogonal axes. There are no gravity effects anywhere.