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.
A) 350 J
- The initial internal energy of the cup is
- The final internal energy of the cup is

According to the first law of thermodynamics:

where
Q is the heat absorbed by the system
W is the work done on the system
The work done on the system in this case is 0, so we can rewrite the equation as

And so we find the heat transferred

B) IN the cup
Explanation:
in this situation, we see that the internal energy of the cup increases. The internal energy of an object/substance is proportional to its temperature, so it is a measure of the average kinetic energy of the molecules of the object/substance. Therefore, in this case, the temperature (and the energy of the molecules of the substance) has increased: this means that heat has been transferred INTO the system from the environment (the heat came from the sun).
The x component of the force is 8.4N * cos(31°) = 7.2N (2 s.f.)
Speed= distance/ time so distance = speed * time= 28 * 20= 560m .. so the answer is 560m.. l hope it helped :)