Answer:
A. potential energy is 258720 Joule
Explanation:
A.Gravitational potential energy is: PE = m × g × h
velocity = 15.33 m/s when the car reaches the bottom of the hill.
where, m = mass
g = acceleration due to gravity
h = height from the bottom of hill.
The potential energy is : m×g×h
=(2200×9.8×12)
=258720 Joule
B. at the bottom of the hill, the potential energy is converted into kinetic energy so PE at top = KE at bottom
kinetic energy= 
(
)
where v = velocity
m= mass
therefore, v=
or, v=
or, v=15.33 m/s
Force. Force is measured by newtons, probably because he came up with the equations to calculate force.
Hope this helps!
Answer:
The angular velocity is 
Explanation:
From the question we are told that
The mass of wooden gate is 
The length of side is L = 2 m
The mass of the raven is 
The initial speed of the raven is 
The final speed of the raven is 
From the law of conservation of angular momentum we express this question mathematically as
Total initial angular momentum of both the Raven and the Gate = The Final angular momentum of both the Raven and the Gate
The initial angular momentum of the Raven is 
Note: the length is half because the Raven hit the gate at the mid point
The initial angular momentum of the Gate is zero
Note: This above is the generally formula for angular momentum of square objects
The final angular velocity of the Raven is 
The final angular velocity of the Gate is 
Substituting this formula
![\frac{1}{3} m_g L^2 w = m_r * \frac{L}{2} * [u_r - v_r]](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B3%7D%20m_g%20L%5E2%20w%20%20%20%3D%20%20%20%20m_r%20%2A%20%20%5Cfrac%7BL%7D%7B2%7D%20%2A%20%5Bu_r%20-%20v_r%5D)
Where 
is the angular velocity
Substituting value
![\frac{1}{3} (4.5)(2)^2 w = 1.2 * \frac{2}{2} * [5 - 1.5]](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B3%7D%20%284.5%29%282%29%5E2%20%20w%20%20%20%3D%20%20%20%201.2%20%2A%20%20%5Cfrac%7B2%7D%7B2%7D%20%2A%20%5B5%20-%201.5%5D)
First of all, we need to write the First Law of thermodynamics assigning the correct sign convention:
where
is the change in internal energy of the system
Q is the heat absorbed/released
W is the work done
and the signs are assigned based on whether there is an increase in the internal energy or not. Therefore:
Q is positive if it is absorbed by the system (because internal energy increases)
Q is negative if it is released by the system (because internal energy decreases)
W is negative if it is done by the system on the surrounding (because internal energy decreases)
W is positive if it is done by the surrounding on the system (because internal energy increases)
Using these definitions, we can now fill the text of the question:
When a system is heated, heat is ABSORBED by the system. The amount of heat added is given a POSITIVE sign. When a system is cooled, heat is RELEASED by the system. The amount of heat is given a NEGATIVE sign. If a gas expands, it must push the surrounding atmosphere away. Thus, work is done BY the system and is given a NEGATIVE sign. If a gas is compressed, then work is done ON the system. This work is given a POSITIVE sign.
The idea of a mechanical device, like a wind up toy, is to take take advantage of the laws of thermodynamics in order to perform some kind of work.
In the case of a wind up toy, mechanical energy (winding the handle) is stored as potential energy in an internal spring. This creates a state of 'low entropy' in the toy since work was done to concentrate energy in the spring.
The natural tendency of the spring is to unwind and distribute it's energy in a more disordered fashion, thereby increasing entropy and following the laws of thermodynamics.
The mechanism inside the toy is engineered to focus the flow of energy being delivered by the spring into a specific mechanical motion (Kinetic Energy), then sound (air pressure) and finally heat (thermal energy).
