Answer:

Explanation:
As we know that the formula of range is given as

now we know that
maximum value of the range of the projectile is given as

now we need to find such angles for which the range is half the maximum value
so we will have




<u>Answer:</u> The number of electrons in given amount of silver are 
<u>Explanation:</u>
To calculate the number of moles, we use the equation:

We are given:
Given mass of silver = 7.1 g
Molar mass of silver = 107.87 g/mol
Putting values in above equation, we get:

Number of electrons in 1 atom of silver = 47
According to mole concept:
1 mole of an element contains
number of particles
So, 0.066 moles of silver will contain = -
number of electrons
Hence, the number of electrons in given amount of silver are 
A motion security line is a system that is used to detect motion.
The input for the system is MOTION and the output is LIGHT. That is, when the system detects motion it switch on light.
Remember, an Input is the information that was inserted into a system while the output is the result of the processed information.
The answer is the last choice.
Its electrical potential energy stays the same because it has the same electric potential. The reason why is that moving the charge towards X does not change the distance of the negative charge between the plates. The Electrical potential energy of a particle is the result energy by virtue of its position from the electrical fields produce by the plates both positive and negative. Since the charge is still equidistant to each other (assuming based from the diagram) no change in terms of electrical energy consumption or work was done.