Answer Happy

3) Figuring it all out: From the East a person on foot approaches a crosswalk at a constant speed of 1.3 m/s (3 mph). The person is 10 meters away from the crosswalk. From the West a person on a bike speeds toward the crosswalk at a speed of 8.9 m/s (20 mph). The bike is 20 meters away from the crosswalk. The crosswalk is 6 meters across (in the sidewalk direction) and 10 meters across (in the car direction). A car approaches the crosswalk going North with a constant speed of 9.83 m/s (22 mph) and is 10 meters away. Does the car hit the bike or pedestrian? Let's just assume that if the bike or pedestrian are 1 meter into the crosswalk, that's a hit. The car does not slow down. 1) Draw a diagram showing the situation. -> North should be up and west to the left. 2) Write out all the known variables for the car, the pedestrian and the biker. Speed, distance, time, acceleration if applicable. Car Pedestrian Biker 3) The key here is how long before the car is in the crosswalk and will the biker and pedestrian be in the crosswalk by that time. Estimate the time it takes for the car to get to the crosswalk. (x = x + Vot + 1/2at²). You can assume x, = 0. Is a = 0 as well? yes no 4) Now with that time, how far does the pedestrian go? Do they get hit? Why or why not? 5) How far does the bike go? Do they get hit? Why or why not?