<span>They are balanced. If the forces were not balanced the book would move*. In this example, the downward force of gravity on the book is counterbalanced by the upthrust of the desk. </span>
The answer to question one is A.
The answer to question two is A.
The answer to question three is D.
Answer:
THE RUBBER BALL
Explanation:
From the question we are told that
The mass of the rubber ball is 
The initial speed of the rubber ball is 
The final speed at which it bounces bank 
The mass of the clay ball is 
The initial speed of the clay ball is 
The final speed of the clay ball is 
Generally Impulse is mathematically represented as
where
is the change in the linear momentum so

For the rubber is


=> 
For the clay ball


=> 
So from the above calculation the ball with the a higher magnitude of impulse is the rubber ball
Answer:
The number of turns in the solenoid is 230.
Explanation:
Given that,
Rate of change of current, 
Induced emf, 
Current, I = 1.5 A
Magnetic flux, 
The induced emf through the solenoid is given by :

or
........(1)
The self inductance of the solenoid is given by :
.........(2)
From equation (1) and (2) we get :

N is the number of turns in the solenoid


N = 229.28 turns
or
N = 230 turns
So, the number of turns in the solenoid is 230. Hence, this is the required solution.