A straight rod of length extends from to

PHYSICS · Single correct · AP · Physics C: Electricity and Magnetism · Electric Charges Fields and Gauss's Law · Electric Charges Fields and Gauss's Law

Problem

A straight rod of length LL extends from x=ax = a to x=L+ax = L + a. The gravitational force it exerts on point mass ' mm ' at x=0x = 0 , if the mass per unit length of the rod is A+Bx2A + Bx^2 , is given by: (1) Gm[A(1a+L−1a)−BL]Gm \left[ A \left( \frac{1}{a+L} - \frac{1}{a} \right) - BL \right] (2) Gm[A(1a−1a+L)−BL]Gm \left[ A \left( \frac{1}{a} - \frac{1}{a+L} \right) - BL \right] (3) Gm[A(1a+L−1a)+BL]Gm \left[ A \left( \frac{1}{a+L} - \frac{1}{a} \right) + BL \right] (4) Gm[A(1a−1a+L)+BL]Gm \left[ A \left( \frac{1}{a} - \frac{1}{a+L} \right) + BL \right]

Related theory

Browse the problem library