Answer:
The force acting on the ball is 92.4 N.
Explanation:
Given that,
Initial speed of the ball, u = 0
Final speed of the ball, v = 31.6 m/s
The average power generated during the serve is 2920 W. Power generated by an object is given by :

W is the work done, W = Fd

Since, 
So,

F is the force acting on the ball

So, the force acting on the ball is 92.4 N. Hence, this is the required solution.
Answer:
20 J
Explanation:
Kinetic energy is given as half of the product of mass and the square of velocity of an object:
KE = 
where m = mass = 40 kg
v = velocity = 1 m/s
Hence, Mary's kinetic energy is:
KE = 
KE = 20 * 1 = 20 J
She has a kinetic energy of 20 J.
Answer:
Explanation:
Given
charge of first body 
charge of second body 
Particle 1 is at origin and particle 2 is at 
third Particle which charge +q must be placed left of
because it will repel the q charge while
will attract it
suppose it is placed at a distance of x m








Answer:
um how about no.. this is not the site for what you're looking for...
Explanation:
Answer:
A. The model was the result of hundreds of years of experiments.
Explanation:
Since it is not possible to visualize an atom in isolation, scientists have spent hundreds of years experimenting and creating atomic models, that is, images that serve to explain the constitution, properties and behavior of atoms.
The earliest who imagined the existence of the atoms were the Greek philosophers Leucippus and Democritus in about 450 BCE. According to them, everything would be formed by tiny indivisible particles. Hence the origin of the name "atom", which comes from the Greek a (no) and tome (parts).
But in the nineteenth century, some scientists began to conduct experimental tests increasingly accurate thanks to technological advances. Not only was it discovered that everything was actually made up of tiny particles, but it was also possible to understand more and more about the atomic structure.
Scientists used the information discovered by other scholars to develop the atomic model. In this way, the discoveries of one scientist were replaced by those of others. The concepts that were correct remained, but those that proved to be non-real were now abandoned. Thus, new atomic models were created. This series of discoveries of the atomic structure until arriving at the accepted models today was known like the evolution of the atomic model.