Tangential and Radial Acceleration

[CactuarEnigma]

A train slows down as it rounds a sharp horizontal turn, slowing from 90.0 km/h to 50.0 km/h in the 15.0 s that it takes to round the bend. The radius of the curve is 150 m. Compute the acceleration at the moment the train speed reaches 50.0 km/h. Assume it continues to slow down at this time at the same rate.

So if at = d|v| / dt, what is the function to evaluate? I think calculus fell out of my head over the summer. Thanks for your time.

 

[Doc Al]

Calculus is not needed, if you are familiar with kinematics and centripetal acceleration. Find the tangential and radial components of the acceleration. The tangential component is uniform (figure it out using kinematics); the radial component depends on the speed and the radius.