Answer:
The horse is going at 12.72 m/s speed.
Explanation:
The initial speed of the horse (u) = 3 m/s
The acceleration of the horse (a)= 5 m/
The displacement( it is assumed it is moving in a straight line)(s)= 15.3 m
Applying the second equation of motion to find out the time,



Solving this quadratic equation, we get time(t)=1.945 s, the other negative time is neglected.
Now applying first equation of motion, to find out the final velocity,



v=12.72 m/s
The horse travels at a speed of 12.72 m/s after covering the given distance.
At stp conditions (

), the speed of sound is

The sound wave moves by uniform motion, so we can use the basic relationship between space, time and velocity:

where S is the distance covered by the sound wave in a time t. In our problem, t=3.00 s, therefore the distance covered by the sound wave is
Answer:
Energy cannot be changed from one form to another without a loss of usable energy
Explanation:
Second law of thermodynamics states that the total entropy or the randomness of the system remains constant over time. It also states that the net entropy will remain the same or it will increase.
Entropy of a system is given by heat absorbed divided by temperature. It is given by :

So, the correct option is (A) "Energy cannot be changed from one form to another without a loss of usable energy".
This relationship is called commensalism.