A level physics Electric fields question (2)

For this question I got the answer right but I just used common sense/intuition. Could someone explain why the answer is c with actual physic formulas to back it up please

(edited 1 month ago)

Reply 1

pat8314

Velocity of satellite = root(GM/R)
Thus when R decreases V increases since G and M are constants
Time period of a satellite, T^2 = R^3 and now since R reduces T should also reduce assuming its a big quantity

Reply 2

Eimmanuel

Study Forum Helper

Original post by 1234kelly

For this question I got the answer right but I just used common sense/intuition. Could someone explain why the answer is c with actual physic formulas to back it up please

Wow, you must have very good intuition. :smile:

Just to add to what pat8314, the relationship between the period of the satellite/planet and the radius of the orbit is known as Kepler's third law is
T² = kR³ where k is some constants.
Do not write T² = R³, you can easily mark down in some situations if you are answering the structured question.