Question

Chapter 8 Question 2

In the figure, a frictionless roller coaster car of mass m = 824 kg tops the first hill with speed vo = 18.0 m/s at height h = 45.0 m. What is the speed of the car at (a) point A, (b) point B, and (c) point C? (d) How high will the car go on the last hill, which is too high for it to cross? Use g=9.81 m/s2. First hill B h h h/2 (a) Number Units (b) Number Units (c) Number Units (d) Number Units

Answer 1

Solution : , Vo = 18 m/s , h = 45m mass=m= = 824 P. Vo B h h "to cal Applying conservation of mechanical energy at point p aut A get migh at must ragh + 2 munt we - - kmuo? ਤੇ ਆਪਾ A VA= Vo 18m 18 Velocity at A = VA = 18mle.

Cle) Applying Conservation of mechanical energy at Point A and B. (P.E), +(k. EA (P. Eh t (KE) Where Poet kie - Potential En Energy Kinetic Ene nergy migh + + mvp² £mus? 2 mgh + 2 mua ngh I mva? 2 gh VB² 9.8x45 +(1872 = 324 t uul VB² = VR? Vg - 27.7 mls = Velocity Velocity at Point BY (co of energy - Conservation mechanical at Point B and f Źh UB2+ ing A t th Veh Up? Vc? (27.7)? + 9.88 US =ve? 7 6 5 t uul = vc? + gh 2 Vc = 34.73 mg at point ei

(2) let it rises to height Hugh' o o I move? h' 11 Vez ng 61-54m ch reached 61-sum os height