Answer:
The acceleration at lowest point is 19.62 m/s^2
Explanation:
Conservation of energy is an concept in which it is stated that the energy of an isolated object remains the same. Energy changes from one form to another.
Lets Assume
Constant of string is K
By using the conservation of energy we will have the following equation
1/2 x 80^2 x K = m x 9.81 x 120
3200 K = 1177.2 m
K = 1177.2 m / 3200
K = 0.368 m
At the lowest point we will have
a = ( K x X - m x g ) / m
a = ( 0.368 m x 80 - m x 9.81 ) / m
a = 19.62 m / s^2
So, the acceleration at lowest point is 19.62 m/s^2
Answer:
Liquid
Explanation:
Before anything evaporates, it is in a liquid state.
Take into account that density and relative density are given by:

Take into account that the volume associated to each of the given sustances in the table is determined by the Level Difference (because it is the change in the volume of the water of the recipient in which the substance is immersed).
The density of water in kg/m^3 is 1000 kg/m^3.
Due to the density must be given in kg/m^3, it is necessary to express the volumes of the table in m^3 and mass in kg, then, consider the following conversion factor:
1 m^3 = 1000000 ml
1 kg = 1000 g
Then, you obtain the following results:
Brass:

Cooper:
Given:
The force of attraction is F = 48.1 N
The separation between the charges is

Also, the magnitude of charge q1 = q2 = q.
To find the magnitude of charge.
Explanation:
The magnitude of charge can be calculated by the formula

Here, k is the Coulomb's constant whose value is

On substituting the values, the magnitude of charge will be

Thus, the magnitude of each charge is 9.91 x 10^(-4) micro Coulombs.
Answer:
Option D.
Value cannot be calculated without knowing the speed of the train
Explanation:
The speed of the beam can only be calculated accurately when the speed of the train is put into consideration. Based of the theory of relativity, the observer is on the ground, and the train is moving with the beam of light inside it. This causes a variation in the reference frames when making judgements of the speed of the beam. The speed of the beam will be more accurate if the observer is moving at the same sped of the train, or the train is stationary.
To get the correct answer, we have to subtract the speed of the train from the speed calculated.