1. A brick is thrown upward from the top of a building at an angle of 25o to the horizontal and with an initial speed of 15 m/s. The brick hits the ground after 3.0 s of flight. (a) Calculate the height of the building. [Label all kinematics charts clearly.] (b) Suggest what kind of building this might be, and whether this brick was thrown by hand or with a brick cannon. Justify your answer as you would to a non-physicist. (c) State the magnitude and direction of the brick’s velocity and acceleration vectors at the instant after the brick was released. Justify your answers. (d) State the magnitude and direction of the brick’s velocity and acceleration vectors at the instant when the brick was at the highest point of its flight. Justify your answers. (e) State the magnitude and direction of the brick’s velocity and acceleration vectors at the instant immediately before the brick hit the ground. Justify your answers.

Amass m = 74 kg slides on a frictionless track that has a drop, followed by a loop-the-loop with radius r = 18.4 m and finally a flat straight section at the same height as the center of the loop (18.4 m off the ground). since the mass would not make it around the loop if released from the height of the top of the loop (do you know why? ) it must be released above the top of the loop-the-loop height. (assume the mass never leaves the smooth track at any point on its path.) 1. what is the minimum speed the block must have at the top of the loop to make it around the loop-the-loop without leaving the track? 2. what height above the ground must the mass begin to make it around the loop-the-loop? 3. if the mass has just enough speed to make it around the loop without leaving the track, what will its speed be at the bottom of the loop? 4. if the mass has just enough speed to make it around the loop without leaving the track, what is its speed at the final flat level (18.4 m off the ground)? 5. now a spring with spring constant k = 15600 n/m is used on the final flat surface to stop the mass. how far does the spring compress?