Question Number 227903 by mr W last updated on 26/Feb/26
Commented by mr W last updated on 27/Feb/26
Commented by mr W last updated on 27/Feb/26
$${G}_{{R}} ={weight}\:{of}\:{rod}\:\left({position}\:{unchanged}\right) \\ $$$${G}_{{B}} ={weight}\:{of}\:{ironp}\:{ball}\:\left({position}\:{unchanged}\right) \\ $$$${G}_{{T}} ={weight}\:{of}\:\:{tank}\:\left({position}\:{unchanged}\right) \\ $$$${G}_{{w}} ={weight}\:{of}\:{water}\:\left({position}\:{changed}\right) \\ $$
Commented by mr W last updated on 27/Feb/26
$${the}\:{sum}\:{of}\:{forces}\:{in}\:{both}\:{supports}\: \\ $$$${together}\:{is}\:{the}\:{sum}\:{of}\:{the}\:{weights} \\ $$$${from}\:{the}\:{tank},\:{water},\:{bar}\:{and}\:{the} \\ $$$${ball}.\:{since}\:{the}\:{total}\:{weight}\:{from} \\ $$$${them}\:{is}\:{not}\:{changed},\:{so}\:\: \\ $$$${N}_{\mathrm{1}} +{N}_{\mathrm{2}} \:{must}\:{be}\:{constant},\:{so} \\ $$$${C}\:{can}\:{not}\:{be}\:{true}. \\ $$
Commented by mr W last updated on 27/Feb/26
$${when}\:{the}\:{ball}\:{becomes}\:{immersed}\:{in} \\ $$$${water},\:{the}\:{COM}\:{from}\:{the}\:{water}\: \\ $$$${moves}\:{a}\:{little}\:{bit}\:{in}\:{direction}\:{to}\:{N}_{\mathrm{1}} . \\ $$$${therefore}\:{N}_{\mathrm{1}} \:{will}\:{increase}\:{and}\:{N}_{\mathrm{2}} \\ $$$${will}\:{decrease}.\:\Rightarrow{Answer}\:{A}\:{is}\:{true}. \\ $$
Commented by fantastic2 last updated on 27/Feb/26
$${i}\:{say}\:{C} \\ $$
Commented by mahdipoor last updated on 26/Feb/26
$$\mathrm{i}\:\mathrm{sey}\:\mathrm{A}.\:: \\ $$$$\mathrm{As}\:\mathrm{the}\:\mathrm{iron}\:\mathrm{ball}\:\mathrm{sinks}\:\mathrm{its}\:\mathrm{weight}\:\mathrm{which} \\ $$$$\mathrm{is}\:\mathrm{more}\:\mathrm{on}\:\mathrm{the}\:\mathrm{right}\:\left(\mathrm{N}_{\mathrm{2}} >\mathrm{N}_{\mathrm{1}} \right),\:\mathrm{is}\:\mathrm{distriuted}\:\mathrm{equally} \\ $$$$\mathrm{between}\:\mathrm{supports}. \\ $$