How Long Does Tara Have Before She Crashes?

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In summary, Tara has a speed of 27 m/s and limited visibility of 30m due to fog. She suddenly sees a car in front of her traveling at 10 m/s in the same direction. If she fails to apply the brakes, she has approximately 2 seconds before crashing into the car. This can be determined by simplifying the problem and using the known distance and speeds of the vehicles.
  • #1
thehatchetmen
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Tara is driving at 27 m/s through a fog that limits her visibility to 30m. She suddenly sees a car in front of her traveling in the same direction at 10 m/s. if she fails to apply the brakes, how much time does she have between seeing the car and crashing into it?


how do you do this question?
 
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  • #2
You know her speed, and you know the distance between the two vehicles when she sees it. You also know the speed of the vehicle ahead. You have everything that you need. What do you need to derive to determine the elapsed time?
 
  • #3
Since the second car only could have be seen 30m ahead he is starting 30m, and Tara starts with 0. Then after the first second Tara is at 27m and the second car is at 40m. At the 2nd second the second car is at 50m and Tara is at 54m, meaning she would have crashed at about 2 seconds
 
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  • #4
Think. Is there another way to simplify this problem without calculating the actual positions of the vehicles at each unit of time?
 

1. What is the concept of speed?

Speed refers to the rate at which an object moves or the distance an object travels in a specific amount of time. It is typically measured in units such as meters per second or miles per hour.

2. How do you calculate speed?

Speed can be calculated by dividing the distance traveled by the time it took to travel that distance. The formula for speed is: speed = distance/time.

3. What are the different types of speed?

The three main types of speed are average speed, instantaneous speed, and constant speed. Average speed is the total distance traveled divided by the total time it took, instantaneous speed is the speed at a specific moment in time, and constant speed is when an object travels at the same speed without changing.

4. How does speed differ from velocity?

Speed and velocity are often used interchangeably, but they are actually different concepts. Speed is the rate of motion, while velocity is the rate of motion in a specific direction. Velocity takes into account the direction of an object's movement, whereas speed does not.

5. What factors can affect an object's speed?

An object's speed can be affected by various factors, including the object's mass, the amount of force applied to it, and the presence of external forces such as friction or air resistance. Additionally, the surface the object is traveling on and the object's shape can also impact its speed.

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