Answer:
v=5.86 m/s
Explanation:
Given that,
Length of the string, l = 0.8 m
Maximum tension tolerated by the string, F = 15 N
Mass of the ball, m = 0.35 kg
We need to find the maximum speed the ball can have at the top of the circle. The ball is moving under the action of the centripetal force. The length of the string will be the radius of the circular path. The centripetal force is given by the relation as follows :

v is the maximum speed

Hence, the maximum speed of the ball is 5.86 m/s.
Answer:
3.0883 x 10^10mg
Explanation:
1 kilogram = 1000 000 milligrams
So, 30 883 x 1000 000 = 30 883 000 000mg
Answer:
9.73 x 10⁻¹⁰ m
Explanation:
According to Heisenberg uncertainty principle
Uncertainty in position x uncertainty in momentum ≥ h / 4π
Δ X x Δp ≥ h / 4π
Δp = mΔV
ΔV = Uncertainty in velocity
= 2 x 10⁻⁶ x 3 / 100
= 6 x 10⁻⁸
mass m = 0.9 x 10⁻¹⁵ x 10⁻³ kg
m = 9 x 10⁻¹⁹
Δp = mΔV
= 9 x 10⁻¹⁹ x 6 x 10⁻⁸
= 54 x 10⁻²⁷
Δ X x Δp ≥ h / 4π
Δ X x 54 x 10⁻²⁷ ≥ h / 4π
Δ X = h / 4π x 1 / 54 x 10⁻²⁷
= 
= 9.73 x 10⁻¹⁰ m