- #1
blanny
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Hi, this one is probably easy, but I just can't wrap my head around it.
You are arguing over a cell phone while trailing an unmarked police car by 25m; both your car and the police car are traveling 110km/h (about 31m/s). You take your eye off the road for 2.0s because of the argument. At the very beginning of the 2.0s, the police car brakes at 5m/s^2
a) what is the separation between the two cars when your attention returns?
I worked it out and I got about 20m. Is this about right?
b) Suppose you take another .40s to realize the danger and begin braking. If you too brake at 5m/s^2, what is your speed when you hit the police car?
I'm not too sure how to set this one up. I'm thinking it has to be a system of equations...
after 2.4s the distance should be 19m, but how do I set up the system from there?
The equations in the chapter are the equations for motion with constant acceleration.
thanks
Matt
You are arguing over a cell phone while trailing an unmarked police car by 25m; both your car and the police car are traveling 110km/h (about 31m/s). You take your eye off the road for 2.0s because of the argument. At the very beginning of the 2.0s, the police car brakes at 5m/s^2
a) what is the separation between the two cars when your attention returns?
I worked it out and I got about 20m. Is this about right?
b) Suppose you take another .40s to realize the danger and begin braking. If you too brake at 5m/s^2, what is your speed when you hit the police car?
I'm not too sure how to set this one up. I'm thinking it has to be a system of equations...
after 2.4s the distance should be 19m, but how do I set up the system from there?
The equations in the chapter are the equations for motion with constant acceleration.
thanks
Matt