Practice Problem 1.7 Review | Constants Part A A firefighting crew uses a water cannon that shoots water at 29.0 m/s at a fixed angle of 47.0 above Find d1 the horizontal. The firefighters want to direct the Express your answer in meters. water at a blaze that is 11.0 m above ground level. How far from the building should they position their cannon? There are two possibilities (d1 Review | Constants Part A A physics professor leaves her house and walks along the sidewalk toward campus. After 5 min she realizes that it is raining and returns home. The At which of the labeled points is her velocity zero? distance from her house as a function of time is shown in the figure below.(Figure 1) Please Choose v Submit Request Answer Part B Figure Review | Constants R = \\Rx2 + Ry? = (31.3 cm) + (57.9 cm)2 = 66 cm From the definition of the inverse tangent, we have Now we'll use the component method to add two vectors. We will use this technique extensively when we begin to 0 = tan-1 Ry = tan-1 57.9 cm = 620 consider how forces act upon an object. Vector A has a magnitude of 50 cm and a direction of 30, and vector B 31.3 cm has a magnitude of 35 cm and a direction of 110. Both angles are measured counterclockwise from the positive x axis. Use components to calculate the magnitude and direction of the vector sum (i.e., the resultant) Part (b) of (Figure 1) shows this resultant vector and its R = A + B. components. REFLECT We used the components of the vector sum R to find its magnitude and direction. Note how important it was to Figure recognize that the x component of B is negative. Part A - Practice Problem: B Ry = Ay + By Find the magnitude of the vector sum of these two vectors R =A +B by using components: 65 m , 55 ; 70 m , 125 Express the magnitude in meters to the nearest integer. TBy B (35 cm) iAy A Note that By 110 (50 cm) ! is negative. AED 30 Ax By O RX = Ar + BJ magnitude (a) Our diagram for this problem (b) The resultant R and its componentsPractice Problem 1.7 Multiple Choice Problem 4.13 Multiple Choice Question 1.7 15 of 25 Review | Constants Part A Your car gets 39.1 mi/ga on a trip. How many kilometers/liter did it get? (3.79 | = 1 gal; 1 mi = 1.61 km) 36.6 km/l O 63.0 km/ 10.3 km/ 16.6 km/l Submit Request