A car is travelling at 10m/s when it brakes and decelerates at 2ms^-2 to a stop. How long does the car take to stop?
This is a question testing the knowledge of the equations of constant acceleration (Suvat equations)First convert the question into a standard form. For example by writing out the variables as follows s (displacement) = unknownu (initial velocity) = 10m/sv (final velocity) = 0m/sa (acceleration) = 2ms^-2t (time) = unknownYou know v, u and a and you want to calculate t, therefore the equation you need to use is v = u + a*tRe-arranging t = (v - u) / a Finally substituting in v, u and a, t = (10 - 0) / 2 = 5sSo the time taken for the car to stop is 5 seconds.
KM
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