Explanation:
Given that,
The mass of rock, m = 2.35-kg
It was released from rest at a height of 21.4 m.
(a) The kinetic energy is given by : 
As the rock was at rest initially, it means, its kinetic energy is equal to 0.
(b) The gravitational potential energy is given by : 
It can be calculated as :

(c) The mechanical energy is equal to the sum of kinetic and potential energy such that,
M = 0 J + 492.84 J
M = 492.84 J
Hence, this is the required solution.
Question:
What two forces are balanced in what we call gravitational equilibrium?
A) the electromagnetic force and gravity
B) outward pressure and the strong force
C) outward pressure and inward gravity
D) the strong force and gravity
E) the strong force and kinetic energy
Answer:
The correct answer is C) Outward Pressure and Inward gravity
Explanation:
Gravitational equilibrium is a balance between the inward pull of gravity and the outward push of internal gas pressure. It also refers to the condition of a star in which the weight of overlying layers at each point is balanced by the total pressure at that point.
As the weight increases in the lower layers of the sun, the pressure also increases to maintain this balance. So you find that the outward push of pressure balances the inward pull of gravity thus creating an equilibrium.
Why is gravitational equilibrium important?
The simple answer is <u>balance. </u> If for instance the sun as a stable star (which has gravitational equilibrium) loses it's balance, it becomes highly unstable and prone to violent outbursts. These outbursts are caused by the very high radiation pressure at the star's upper layers, which blows significant portions of the matter at the "surface" into space during eruptions that may rage for several years. Of course such a condition is adverse to the existence and support of life.
Cheers!
1. C
2. A
3. E
4. D
5. B
6. F
i might have 2 and 6 mixed up, not completely sure tho
Answer:
The ratio of lengths of the two mathematical pendulums is 9:4.
Explanation:
It is given that,
The ratio of periods of two pendulums is 1.5
Let the lengths be L₁ and L₂.
The time period of a simple pendulum is given by :

or

Where
l is length of the pendulum

or
....(1)
ATQ,

Put in equation (1)

So, the ratio of lengths of the two mathematical pendulums is 9:4.