Question

An initially motionless test car is accelerated uniformly to 120 km/h in 8.28 s before striking a simulated deer. The car is in contact with the faux fawn for 0.815 s, after which the car is measured to be traveling at 71.0 km/h. What is the magnitude of the acceleration of the car before the collision

Answer 1

Answer:

The value is   $a = 4.0 \ m/s^2$

Explanation:

From the question we are told that  

  The velocity  is  $a = 120 \ km/h = [tex]\frac{120 * 1000}{3600} = 33.3 \ m/s$[/tex]

  The time taken is $t = 8.28 \ s$

    The  time taken for contact is  $t_c = 0.815 \ s$

     The  velocity of the of the car after contact is $v_c = 71.0 \ km/h = [tex]\frac{71 *1000}{3600} = 19.7 2 \ m/s$[/tex]

From the equation of kinematics we have that  

       $v = u + at$

Here   u =  0 \ m/s  since the car is initially motionless

=>    $33.3 = 0 + a * 8.28$

=>    $a = 4.0 \ m/s^2$