Answer:
The velocity of the student has after throwing the book is 0.0345 m/s.
Step-by-step explanation:
Given that,
Mass of book =1.25 kg
Combined mass = 112 kg
Velocity of book = 3.61 m/s
Angle = 31°
We need to calculate the magnitude of the velocity of the student has after throwing the book
Using conservation of momentum along horizontal direction
![m_(b)v_(b)\cos\theta= m_(c)v_(c)](https://img.qammunity.org/2020/formulas/physics/college/epppyxxpewyjfharrxykyr0sfykolzlfjh.png)
![v_(s)=(m_(b)v_(b)\cos\theta)/(m_(c))](https://img.qammunity.org/2020/formulas/physics/college/pen07eycflwfgpjxsr0ojcut5e56pylk4u.png)
Put the value into the formula
![v_(c)=(1.25*3.61*\cos31)/(112)](https://img.qammunity.org/2020/formulas/physics/college/62u6d2xauuw19qn8c9dqmtk22r6y11hasd.png)
![v_(c)=0.0345\ m/s](https://img.qammunity.org/2020/formulas/physics/college/x1y0bsdt9rvajcxsyndwsqmvezt4ly5c9q.png)
Hence, The velocity of the student has after throwing the book is 0.0345 m/s.