Question
Faheem was standing at the Cullen-Holman intersection near the stadium garage to cross Cullen Blvd and rain started falling vertically down. Using the knowledge acquired from Phys 1321 course, he estimated the speed of the rain as about 8 m/s. At the same time Kelsey was coming in a car through the Cullen Boulevard and crossing the intersection at a constant speed of 50 km/h. At what angle from the vertical did the rain drops appear to be falling as viewed by Kelsey? A. 0 degree B. 60 degree C. 81 degree D. 9 degree E. 30 degree Suppose you are standing on a weighing machine (bathroom weighing scale) on an elevator When the elevator is at rest the scale shows 100.0 kg as your mass. The elevator now goes up and reaches a final velocity of 5.0 m/s while travelling a distance of 25.0 m. What is your mass shown by the scale while covering this distance? A. 0.0 kg B. 100.0 kg C. 110.0 kg D. 120.0 kg E. 90.0 kg
Explanation / Answer
here,
the speed of rain , vr = 8 m/s
the speed of cullen , vm = 50 km/h = 13.89 m/s
the angle from the vertical did the rain drops appear to be falling , theta = arctan(vm /vr)
theta = arctan(13.88/8)
theta = 60 degree
the angle from the vertical did the rain drops appear to be falling is B) 60 degree
