1 Two objects of different masses were released from rest near to Earth's surface. Assuming negligible air resistance, are the gradients of the velocity-time graphs for both of the objects the same or different? Explain your answer. 2 An object is released from an unknown height and falls freely for 5 s before it hits the ground. (a) Sketch the velocity-time graph for a time interval of 5 s, assuming there is negligible air resistance. (b) What is the velocity of the object just before it hits the ground? (c) What is the unknown height?