Answer:
E = 16 J
Step-by-step explanation:
Given that,
Mass of a book, m = 2 kg
Velocity of the book from the backpack, v = 4 m/s
We need to find the kinetic energy of the book falling out of the backpack. Due to the motion of the object, kinetic energy is possessed by it. It can be given by :
![E=(1)/(2)mv^2\\\\=(1)/(2)* 2\ kg* (4\ m/s)^2\\\\=16\ J](https://img.qammunity.org/2021/formulas/physics/high-school/gyxdjdoec4g2srof4a84ompdxt8umd7fc7.png)
So, the kinetic energy of the book is 16 J.