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

Related Physics A Level answers

All answers ▸

How do we know the energy of a photon (light particle) is quantised?


Explain the photo-electric effect and how the particle theory of light explains the phenomena. State the equation used to the determine the kinetic energy of a photo-electron and explain the origin of the terms used in your equation.


How do I find how much radioactive material is left after time t if I know its half-life?


State what is meant by isotopes?