### Acceleration of a Sport Car

A sport car moving at 60 Km/H accelerates in the distance of 200 m to the speed of 90 Km/H.

Calculate the acceleration of the car.

 a) 1.51 m/s2 b) 0.45 m/s2 c) 1.22 m/s2 N d) 0.87 m/s2 e) None of the above.

How long does the car take to reach the final velocity?

 N a) 9.5 s b) 7.2 s c) 3.6 s d) 1.6 s e) None of the above.

Solution:

Since the question of this problem is the car acceleration, the first step in solving this problem to  change the units of the two velocities to m/s.

and

This problem can be solved using a single formula, , (U_A_M 5). However, the formula need to be solved for the acceleration.

Substituting the known quantities,

The numerical solution has been finally obtained using MathCAD:

Solution:

After calculating the acceleration of the car, the time needs by the car to reach the final velocity can be calculated with the formula , (U_A_M 3). Again, the time needs to be solved from the above formula,

 by Luis F. Sáez, Ph. D. Comments and Suggestions: LSaez@dallaswinwin.com