okay this is a good conceptual q i think if you really understand it
good solve
soln -> since rod can't provide force on any other dirn than x axis the normal from ground is 6mg (the hinge type shi won't experience any force)
b) momentum cons (let vel of ball be v when ball reaches bottom most pt)
mv=6mu
v=6u
energy cons
2mgl=mv²+6mu²
2gl=v²+6u²
21u²=gl
rt gl/21 =u
now if you observe from inside the cart you will see that the ball is performing circular motion w velocity 7U
and there's no need to applying psuedo force here cuz the tension on the ball doesn't accelerate the cart at this instant
radial accln
T-mg=m(49u²)/l
T= m ( 7g/3)+mg
T=10mg/3
so Normal rxn -> 6mg + 10mg/3
28mg/3
u/allenchd — 18 hours ago