Help urgent mechanics

Help for part d I got 25.6…
I did T minus 10 plus T

As T acts on the string and T-10 as well because of the resistant force which I minused off…
But the answer is actually 25 😭😭😭
Plz can u explain how to do this q

(edited 10 months ago)

Reply 1

mqb2766

If you draw a force triangle the two tensions (identical legs) are at right angles so the resultant force (hypotenuse) is simply pythagoras or simple trig so
T*sqrt(2)

Again, a sketch helps.

(edited 10 months ago)

Reply 2

DFranklin

Just to also point out that you seem to be rounding to 2s.f. (and using the rounded value in subsequent work). So you can't expect your final answer to be correct to more than 2s.f. (and in fact it's quite possible it won't even be correct to 2s.f.)

I would always work to at least 3sf (TBH, I generally did at least 6sf because it just meant no need to worry about roundoff error but it is overkill really)