Physics (Gravitational)

centripetal acceleration

a = rw² = v²/r = vw

(f=ma)

Why magnitude and direction of gravitational field strength is same as centripetal acceleration, ac

1. Magnitude

Gravitational force provides centripetal force

Fg = Fc, mg = mac, g = ac

2. Direction

Towards center of planet

Newton’s law of gravitation→Explaining Fg

Every point mass attracts every other point mass with a force

1. directly proportional to the product of their masses and

2. inversely proportional to the square of the distance between them

Why 2 stars in binary star system experience same magnitude of centripetal force

1. Fg exerted on one star by the other provides centripetal force for each orbit

2. The pair of forces is an action-reaction pair, always equal in magnitude

OR

2. By Newton’s law of gravitation, Fg experienced by each star → ..

GPE at a pt

Total work done to bring a small test mass from infinity to that point

GP $\phi$ , at a pt

Work done per unit mass to bring a small test mass from infinity to that point