1. Problem Statement What is the chance of a light car safely rounding an unbanked frictionless curve compared to a heavy car? Both cars have the same speed and tires. Solution I know that tan(theta)=v^2/(rg) proves that weight does not matter but I do not understand why and my book doesn't explain it very well. Can some one try explaining this concept to me? 2. Problem Statement A rigid massless rod is rotated about one end in a horizontal circle. There is a mass m_1 attached to the center of the rod and a mass m_2 attached to the outer end of the rod. The inner section of the rod sustains three times as much tension as the outer section. Find the ratio m_2/m_1 Solution Doing a force balance at both m_1 and m_2 shows that the centripetal force (F_c=m*v^2/r) will equal the tension. Though since their velocities will not be the same but their angular velocities will be I replaced velocity with radius*angular velocity. F_c=m(rw)^2/r For m_1... 3T=m_1*(rw)^2/r Solve for T, T=m_1*(rw)^2/(3r) For m_2... T=m_2*(2rw)^2/(2r) Since T=T... m_1*(rw)^2/(3r)=m_2*(2rw)^2/(2r) Solving for m_2/m_1 I get 2/3 but my book says the answer is 1/4. Am I wrong or is the book?