C. Energy Conservation 1. A slingshot fires a pebble from the top of a building at a speed of 14.0 m/s. The building is 31.0 m tall. Ignoring all frictional effects, find the speed with which the pebble strikes the ground when the pebble is fired (a) horizontally, (b) vertically straight up, (c) vertically straight down, and (d) at an angle 0 = 27.5' above the horizontal. (28.4 m/s) USE ENERGY TECHNIQUES, not kinematics equations, and think about whether or not it is actually necessary to perform 4 different calculations here. Recall that energy is a SCALAR quantity. 2. A cart slides to the right along a smooth surface and passes position 1 with a speed of 15.0 m/s. Ignore all frictional effects. The vertical height at each numbered position is given in the diagram. a) What is the speed of the cart as it passes position 2? (8.25 m/s} b) Will the cart reach position 4 (numerical calculations are required)? If so, what is it speed as it passes position 4? 3 15.0 m 8.00 m 10.0 m