The speed of the ball moving is

what is momentum?
The momentum p of a classical object of mass m and velocity v is given by pclassical =mv.
For photons with wavelength λ,this equation does not hold.Instead, the momentum of the Photon is given by p Photon = h/λ
where,h is the planck's constant.
The momentum of the red Photon is
given:




since,the Photon and the ping-pong ball have the same momentum,we have



Therefore, if the red photon and the ping-pong ball have the same momentum, the ping-pong ball must have a speed of approximately

learn more about momentum of photon from here: brainly.com/question/28197406
#SPJ4
Answer:
The statement "If a positively charged rod is brought close to a positively charged object, the two objects will repel
" applies to electric charges.
Explanation:
There are only two types of electric charges. Both having own magnitude but different charge.
1. Positive charge
2. Negative charge
Like charges repel each other and opposite charges always attract each other.
When a positively charged rod is brought close to a positively charged object, the rod and the object will repel.
Answer: Option (b) is the correct answer.
Explanation:
Since, there is a negative charge present on the ball and a positive charge present on the rod. So, when the negatively charged metal ball will come in contact with the rod then positive charges from rod get conducted towards the metal ball.
Hence, the rod gets neutralized. But towards the metal ball there is a continuous supply of negative charges. Therefore, after the neutralization of positive charge from the rod there will be flow of negative charges from the metal ball towards the rod.
Thus, we can conclude that negative charge spread evenly on both ends.
Explanation:
A student solving for the acceleration of an object has applied appropriate physics principles and obtained the expression :

Where


m = 7 kg
So, the correct step for obtaining a common denominator for the two fractions in the expression in solving for a is (a) and the value of a is :


Hence, the correct option is (a).