if the speed of the car is incresed to two times the the breaking force to stop the car over the same distance will be
Answers
Originally Answered: If the speed of a car is increased to 2 times, what will be the breaking force needed to stop the car over the same distance?
As others have mentioned, the kinetic energy is 4x greater because it’s a function of the velocity squared. Your question is a little vague because we don’t know what the original stopping distance was as the original reference speed. If the original stopping distance was based on using most or all of the available braking force, then it’s a moot point to try and achieve 4x the braking force. It’s possible the wheels would lock up and you could never achieve the required 4x braking force. So let’s assume the original braking force was modest so that it’s feasible to achieve the required 4x braking force that you need.
There’s an additional wrinkle to take into consideration on getting an exact answer to your question. The wind resistance at 2 times the speed will now become a meaningful factor, so perhaps you only need 3.9x the braking force now. Wind resistance increases at the rate of velocity raised to the 2nd power, same as kinetic energy. I mention this only because at half the speed, the wind resistance is much smaller. At 2x the speed, the wind resistance is a significant factor, depending on speed you are talking about. If you are going 100 MPH, then just letting off the accelerator will result in significant deceleration even without using any braking.
If you were going 5 MPH and wanted to compare to 10 MPH, then it’s basically 4x the braking force, assuming you used modest braking initially so that 4x braking force doesn’t exceed the maximum achievable braking force for the car in question.
If you were going 50 MPH and wanted to compare to 100 MPH, then it’s about 3.8x or 3.9x the braking force, as a rough estimate.
Quick grammar note:
Breakfast = 2 eggs and cup of coffee.
Brake fast = Kid just ran out in front of your car, so stop quickly.
Breaking Bad = Chemistry teacher Walter White with cancer making meth.
Braking Bad = Locking up the wheels and skidding out of control.
Notice the difference?
4 times the original speed
Explanation:
If the speed of the car is doubled in the same distance, then the braking force required to stop the car is four times the original speed i.e. '4v'. Note that all the parameters remain to be same.
hope you understand