Kinematics equations (two objects)

Question

A dragster and a regular car race. The car travels at a constant speed of 28 m/s. 7 seconds later, the dragster accelerates at a rate of 4 m/s^2. What will be the final velocity of the dragster once it catches up to the car?

Answer 1

The race car will travel a distance of 196 m (7s * 28 m/s) before the dragster catches up.   The dragster will cover the same distance.  

 

Now we can use the kinematic equation for an accelerating dragster.

 

Vf² = Vi² + 2 * a * d

 

Vf² = 0 + 2(4m/s^2) *196m

 

Vf = 27.7 m/sec