Answer:
A) Stone will be at the bottom
B) v = 9.46 m/s
Explanation:
We are given;
Circular Radius; R = 0.91m
Tension; T = 40N
Mass of stone; m = 0.37 kg
A) In centripetal acceleration, at the top of a swing, T=mv²/r - mg.
While at the bottom of the swing, T=mv²/r + mg
Thus, from those 2 formulas it's clear that tension will have a higher value at the bottom. Thus, we can deduce that the string will definitely break at the bottom because that is the point where the tension would be the greatest.
B) the string breaks at the bottom, thus,
T=mv²/r + mg
Let's make v the subject where v is speed of stone.
Thus, v = √[(T - mg)(r/m)]
Plugging in the relevant values to get;
v = √[(40 - (0.37 x 9.8))(0.91/0.37)]
v = √89.4604
v = 9.46 m/s