Problem 3 A 5 kg block is sliding at 2 m towards a 1 kg block sliding at -2 m S (a) After impact the blocks separate, the 5 kg block is sliding at 1 m. What is the velocity of the 1 kg block? S (b) A heavy spike has been added to the 5kg block and the two blocks are sent sliding at the same velocities as before. After impact the blocks are stuck together, sliding at a velocity of 1.5 m. What is the mass of the heavy spike? S Problem 4 Suppose you are rowing across a river, as in Figure 1.7 of the textbook. Your speed is 2 miles per hour relative to the current, which is moving at a leisurely 1 mile per hour. If the river is 10 m wide, (a) How far downstream do you end up? (b) To row straight across you would need to have an upstream velocity component (relative to the current). How large would that be? (c) If your rowing speed is still only 2 miles per hour, how long does it take you to row across the river now?