4. Find the acceleration and the tension in the cord of an Atwood's Machine when m₁ = 3 kg and m₂ = 5 kg. 5. How much work is required to accelerate a 1000 kg car from 20 m/s to 45 m/s? 6. The roller coaster shown in the figure below is pulled up to point A where it is released from rest. Assuming no friction, calculate: a) The car speed at points B and C b) The height at which the car speed is 12.5 m/s 32 m B 6 m