We know, by conservation of energy :
Therefore,
Putting given values, we get :
Therefore, the spring be compressed to 6.93 cm to send the ball twice as high.
Hence, this is the required solution.
Kinetic energy lost in collision is 10 J.
<u>Explanation:</u>
Given,
Mass, 
= 4 kg
Speed, 
= 5 m/s
= 1 kg
= 0
Speed after collision = 4 m/s
Kinetic energy lost, K×E = ?
During collision, momentum is conserved.
Before collision, the kinetic energy is
By plugging in the values we get,
K×E = 50 J
Therefore, kinetic energy before collision is 50 J
Kinetic energy after collision:
Since,
Initial Kinetic energy = Final kinetic energy
50 J = 40 J + K×E(lost)
K×E(lost) = 50 J - 40 J
K×E(lost) = 10 J
Therefore, kinetic energy lost in collision is 10 J.
The mass number is the total number of protons and neutrons within an atom and since we know that the unknown element has 6 neutrons, we can simply subtract the number of neutrons from the mass number to get the number of protons.
17 - 6 = 11
There are 11 protons in this unknown element.
Extra:
The number of protons (+) and electrons (-) are equal in a neutral atom so since you know that there are 11 protons you also know that there are 11 electrons. On the periodic table, the element with 11 electrons is Na or Sodium.
Hope this helps! :)
Answer:
First, the different indices of refraction must be taken into account (in different media): for example, the refractive index of light in a vacuum is 1 (since vacuum = c). The value of the refractive index of the medium is a measure of its "optical density": Light spreads at maximum speed in a vacuum but slower in others transparent media; therefore in all of them n> 1. Examples of typical values of are those of air (1,0003), water (1.33), glass (1.46 - 1.66) or diamond (2.42).
The refractive index has a maximum value and a minimum value, which we can calculate the minimum value by means of the following explanation:
The limit or minimum angle, α lim, is defined as the angle of refraction from which the refracted ray disappears and all the light is reflected. As in the maximum value of angle of refraction, from which everything is reflected, is βmax = 90º, we can know the limit angle (the minimum angle that we would have to have to know the minimum index of refraction) by Snell's law:
βmax = 90º ⇒ n 1x sin α (lim) = n 2 ⇒ sin α lim = n 2 / n 1
Explanation:
When a light ray strikes the separation surface between two media different, the incident beam is divided into three: the most intense penetrates the second half forming the refracted ray, another is reflected on the surface and the third is breaks down into numerous weak beams emerging from the point of incidence in all directions, forming a set of stray light beams.
Answer:
E = 16.464 J
Explanation:
Given that,
Mass of tetherball, m = 0.8 kg
It is hit by a child and rises 2.1 m above the ground, h = 21. m
We need to find the maximum gravitational potential energy of the ball. The formula for the gravitational potential energy is given by :
E = mgh
g is acceleration due to gravity
E = 0.8 kg × 9.8 m/s² × 2.1 m
= 16.464 J
So, the maximum potential energy of the ball is 16.464 J.
