Answer:
A
B

C

D

Explanation:
Considering the first question
From the question we are told that
The spring constant is 
The potential energy is 
Generally the potential energy stored in spring is mathematically represented as 
=>
=>
=>
Considering the second question
From the question we are told that
The mass of the dart is m = 0.050 kg
Generally from the law of energy conservation

=> 
=> 
Considering the third question
The height at which the dart was fired horizontally is 
Generally from the law of energy conservation

Here KE is kinetic energy of the dart which is mathematical represented as

=> 
=> 
=> 
Considering the fourth question
Generally the total time of flight of the dart is mathematically represented as

=> 
=> 
Generally the horizontal distance from the equilibrium position to the ground is mathematically represented as

=> 
=> 
It would take 30 minutes
You would do 15.0 divided by 0.5
Answer:
Z = R, i = V/Z, w = √1 / LC
Explanation:
In an RLC circuit the impedance of the circuit is
Z = √[R² + (
)²
Where
= wL
X_{L} = 1 / wC
They are the reactances of the inductor and the capacitor, in this case the current advances to the voltage in the first and is delayed from the voltage in the second, so when the two values give the same reactance the current goes in phase with the voltage and the impedance is minimal
Z = R
V= i Z
i = V/Z
Therefore the current is maximum, this occurs when
w = √1 / LC
Saying that this is the resonant frequency