The main difference between the nebular and condensation theories is that the condensation theory stresses the importance of to the formation of planets.
a.) a nebular cloud
b.) interstellar dust
c.) a flattened disk plane
d.) nuclear fusion

The correct answer is B. Interstellar dust

Just got this question and got it right.

wavelength divides in half and speed stays the same.

initial speed when it is dropped is 150 ft/s

now at the same moment the acceleration due to gravity is perpendicular to its velocity

so as we know that

now we have centripetal acceleration a = 32 ft/s^2 as its perpendicular to velocity

while tangential acceleration at the same moment will be zero

so

now radius of curvature is given as

so the radius of curvature just after it is dropped is 703.125 ft