Finding Time from Accel and Distance

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In summary, the conversation involves finding the time and final speed for a car traveling 0.05 miles with a given acceleration and starting from 0 mph. The equations discussed include time = change/acceleration and d=st, as well as (V_f)^2=(V_i)^2+2a(d_f). The solution is still being worked on and may involve using a constant acceleration to find the time and final speed.
  • #1
BlueBob88
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Not school related, but I guess it could be a homework problem.
I am redoing my racing script on my car game and need some help. I have been looking around in many places and can't seem to find how to do this problem.

Homework Statement


I need to find the time it takes to travel 0.05 miles at a given acceleration starting at a given speed. I also need to find out the final speed.

So if a car starts from a stop (0 mph) and can travel 0-60mph in 7 seconds. How long will it take to travel 0.05 miles and what will its final speed be.

Homework Equations


time = change/acceleration
d=st

The Attempt at a Solution


So far I have its average acceleration at 8.57 mph/s if I can find the time I will be able to find its final speed. If its 1 second it will be 8.75 mph, 2 seconds will be 35mph. (Not to sure on that) But I did (2 seconds^2) * 8.75
 
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  • #2
Is it going to be a constant acceleration? If it is you can use

[tex](V_f)^2=(V_i)^2+2a(d_f)[/tex]

Where [tex]V_f =[/tex] Final Velocity, [tex]V_i =[/tex] Initial Velocity, [tex]d_f =[/tex] the final displacement.

From there you can find the time it takes in a multitude of ways.
 
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  • #3
mph to get the distance.

I would approach this problem by first understanding the relationship between acceleration, distance, and time. The equation d=st can be rearranged to t=d/s, where t is time, d is distance, and s is speed. This means that to find the time it takes to travel 0.05 miles, we need to divide the distance by the speed.

Next, we need to consider the acceleration of the car. From the given information, we know that the car can go from 0-60mph in 7 seconds. This means that the average acceleration during that time period is 60mph/7s = 8.57 mph/s. However, this is the average acceleration and may not be the same as the acceleration at a specific moment in time.

To find the acceleration at a specific moment, we can use the formula a=(vf-vi)/t, where a is acceleration, vf is final velocity, vi is initial velocity, and t is time. In this case, we know that the initial velocity is 0 mph and the final velocity is 60 mph. We also know that the time is 7 seconds. Plugging these values into the equation, we get a= (60mph-0mph)/7s = 8.57 mph/s. This confirms our previous calculation.

Now, to find the time it takes to travel 0.05 miles, we can use the equation t=d/s. Plugging in the values, we get t=0.05 miles/60mph = 0.000833 hours. This is equivalent to 0.05 minutes or 3 seconds. This means that it will take the car 3 seconds to travel 0.05 miles.

To find the final speed, we can use the equation vf=vi+at, where vf is final velocity, vi is initial velocity, a is acceleration, and t is time. Plugging in the values, we get vf= 0mph + (8.57 mph/s)(3s) = 25.71 mph. This means that the car will reach a speed of 25.71 mph after traveling 0.05 miles.

In conclusion, as a scientist, I would approach this problem by first understanding the relationships between acceleration, distance, and time, and then using equations to calculate the desired values. I would also double check my calculations and consider any potential sources of
 

1. How do I calculate time from acceleration and distance?

To find time from acceleration and distance, you can use the equation t = √(2d/a), where t is time, d is distance, and a is acceleration. This equation is derived from the formula d = ½at^2, which represents the relationship between distance, acceleration, and time. By rearranging the formula, you can solve for time.

2. What units should I use for acceleration and distance when calculating time?

When using the formula t = √(2d/a) to find time, it is important to use consistent units for distance and acceleration. For example, if distance is given in meters and acceleration is given in meters per second squared, then the calculated time will be in seconds. It is important to ensure that all units are converted to the same system before plugging them into the formula.

3. Is this equation applicable to any type of motion?

The equation t = √(2d/a) is derived specifically for motion with constant acceleration. This means that the acceleration remains constant throughout the motion. It is commonly used to calculate time for objects falling due to gravity, but it can also be applied to other types of motion with constant acceleration, such as a car accelerating at a constant rate.

4. Can this equation be used to find time for motion with changing acceleration?

No, the equation t = √(2d/a) is only applicable to motion with constant acceleration. For motion with changing acceleration, a more complex equation, such as the quadratic formula, must be used to calculate time. In these cases, it may be helpful to break the motion into smaller segments with constant acceleration and use the above equation for each segment.

5. Are there any limitations to using this equation to find time?

The equation t = √(2d/a) can only be used to find time when distance and acceleration are known. If you are missing one of these variables, then this equation cannot be used. Additionally, this equation assumes that the initial velocity is zero. If this is not the case, then a modified version of the equation must be used, taking into account the initial velocity.

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