Answer: Option (D) is the correct answer.
Explanation:
The given elements Li, C and F are all second period elements. So, when we move from left to right across a period then there occurs increase in number of valence electrons as there occurs increase in total number of electrons.
So, it means more electrons are added to the same energy level.
Thus, we can conclude that a property of valence electrons for each element is located in the same energy level is common in the given elements.
B
I hope this helps and have a wonderful day filled with joy!!
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Answer:
15 meters
Explanation:
The inicial energy of the ball is just potencial energy, and its value is:
E = m * g * h = m * g * 20,
where m is the ball mass, and g is the value of gravity.
In the moment that the ball strickes the ground, all potencial energy transformed into kinetic energy, and 25% of this energy is lost, so the total energy at this moment will be:
E' = 0.75 * E = 0.75 * m * g * 20 = 15*m*g
This kinetic energy will make the ball goes up again, and at the maximum height, all kinetic energy is transformed back into potencial energy.
So, as the mass and the gravity are constants, we can calculate the height the ball will reach:
E' = m*g*h = 15*m*g -> h = 15 meters
Answer:
W = 0.135 N
Explanation:
Given:
- y (x, t) = 8.50*cos(172*x -2730*t)
- Weight of string m*g = 0.0126 N
- Attached weight = W
Find:
The attached weight W given that Tension and W are equal.
Solution:
The general form of standing mechanical waves is given by:
y (x, t) = A*cos(k*x -w*t)
Where k = stiffness and w = angular frequency
Hence,
k = 172 and w = 2730
- Calculate wave speed V:
V = w / k = 2730 / 172 = 13.78 m/s
- Tension in the string T:
T = Y*V^2
where Y: is the mass per unit length of the string.
- The tension T and weight attached W are equal:
T = W = Y*V^2 = (w/L*g)*V^2
W = (0.0126 / 1.8*9.81)*(13.78)^2
W = 0.135 N
Answer:
Work done, W = -318.19 Joules
Explanation:
It is given that,
Force acting on the object, F = 50 N
Distance covered by the force, d = 9 m
Angle between the force and the distance traveled, 
The work done by an object is equal to the product of force and distance traveled. It is equal to the dot product of force and the distance. Mathematically, it is given by :
W = -318.19 Joules
So, the work done by the force is 318.19 Joules. The work is done in opposite to the direction of motion. Hence, this is the required solution.
