Explanation:
It is given that,
Speed of an automobile is 25 km/h or 6.95 m/s
Kinetic energy of the automobile is [tex]10^4\ J[/tex]
(a) Kinetic energy of automobile s given by :
[tex]K=\dfrac{1}{2}mv^2\\\\m=\dfrac{2K}{v^2}\\\\m=\dfrac{2\times 10^4}{(6.95)^2}\\\\m=414\ kg[/tex]
(b) If the velocity of the car is increased to 45 km/hour or 12.5 m/s, new kinetic energy becomes :
[tex]K=\dfrac{1}{2}\times 414\times (12.5)^2\\\\K=32343.75\ J[/tex]
(c) If the velocity is increased to 80 km/hour, 22.23 m/s, So
[tex]K=\dfrac{1}{2}\times 414\times (22.23)^2\\\\K=102293.79\ J[/tex]
Hence, this is the required solution.
