A pendulum bob of mass m, string length ℓ, released from horizontal, collides elastically at the lowest point with a stationary block of mass 5m on a frictionless floor. Which statements are correct just after impact?

Question

G1 Physics · Accepted Answer

Use conservation of linear momentum together with e = (relative speed of separation)/(relative speed of approach). Solving the two collision equations gives A: String tension at lowest point just after collision is (17/9)mg.; B: String tension just before collision is 3mg.; C: Block speed just after collision is (2/3)√(2gℓ).; D: Maximum height reached by bob after impact is 4ℓ/9..