Question

Please help me on Physic

Test 1 September 21, 2018 PHYS 140-1 Do all work in the examination book. 1. Consider the vectors a-i -k and b-j+k a. Find the magnitudes a and b of these vectors. Show work. (4 points) b. Use the dot product to find the angle φ between these vectors. Show work. (6 points) c. Find the cross product ā xb in i, j, k notation by using a determinant. Show work. (8 points) d. Find the magnitude c of the cross product and show that cabsin (). (6 points) 2. A baseball is thrown straight up with an initial speed of 14.7 m/s from the roof of a building H 111.5 m high. (Use the coordinate system shown at the right. Assume the baseball is thrown upward from the edge of the roof, so that it can travel back down to the ground without colliding with the roof. Ignore air resistance. Be sure to include the correct sign and units with any numerical answer. Use g-9.80 m/s2.) Figure 1 a. What are the velocity and acceleration of the baseball when it is at its highest point? (4 points) b. How high does the baseball rise above the roof of the building? (8 points) c. How long does it take the baseball to reach its highest point? (8 points) d. What is the velocity of the baseball when it strikes the ground? (8 points) e. How long is the baseball in the air? (8 points)

Answer 1