Answer:
The velocity of the student has after throwing the book is 0.0345 m/s.
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


Put the value into the formula


Hence, The velocity of the student has after throwing the book is 0.0345 m/s.
Answer:
The acceleration of the ball is 
Explanation:
From the question we are told that
The maximum height the ball reachs is 
The horizontal component of the initial velocity of the ball is
The vertical component of the initial velocity of the ball is 
The vertically motion of the ball can be mathematically represented as

Here the final velocity at the maximum height is zero so 
Making the acceleration
the subject we have

substituting values


The negative sign shows that the direction of the acceleration is in the negative y-axis
In other words, the Earth attracts objects near its surface to itself. This universal force also acts between the Earth and the Sun, or any other star and its satellites. Each attracts the other. Sir Isaac Newton defined this attraction mathematically. Hope this helps! Mark brainly please!