The ballerinas takes advantage of the moment of interia by not stretching her hands out etc. and by doing so decreasing the moment of interia and therefore a smaller torque is produced to rotate at a faster rate.
Answer:

Explanation:
From the question we are told that:
Frictional force 
Coefficient of kinetic friction 
Generally the equation for Normal for is mathematically given by

Therefore


Answer:
D: Scientists have not been successful in disproving the atomic theory.
Explanation:
This theory has had great implications in the understanding of nature at the microscopic level, from the first atomic model to the quantum model of the atom. All modern physics, chemistry and biochemistry are based on the theory that matter is composed of atoms of different elements. It has not been possible to disprove this theory or replace it with a better one.
Answer:
Zero
Explanation:
here, the inductive reactance and the capacitive reactance is same, so this is the condition for resonance.
In the condition for resonance,
the circuit and the voltage in the circuit is in the same phase and the impedance of the circuit is minimum which is equal to the resistance of the circuit.
The phase angle is given by

Ф = 0