Question

At what speed must a 950-kg subcompact car be moving to have the same kinetic energy as a 3.2×104−kg truck going 20 km/h?

Answer 1

Answer:

 950-kg subcompact car be moving to have the same kinetic energy of truck at 116.08 km/hr

Explanation:

  Kinetic energy of body with mass m and moving at velocity v is given by

                  $KE=\frac{1}{2} mv^2$

  KE of truck  $= \frac{1}{2}*3.2*10^4*20^2$

  KE of subcompact car $= \frac{1}{2}*950*v^2$

  Equating

         $\frac{1}{2}*3.2*10^4*20^2= \frac{1}{2}*950*v^2\\ \\ v=116.08 km/hr$

 So 950-kg subcompact car be moving to have the same kinetic energy of truck at 116.08 km/hr