Answer:
Kinetic energy is 1425.11 J.
Explanation:
Given:
Mass of the wrench is, 
Height of fall is, 
Force of resistance is, 
Now, the total energy at the top is equal to the potential energy of the wrench at the top since the kinetic energy at the top is 0.
Now, potential energy at the top is given as:
Now, the potential energy at the top is converted to kinetic energy at the bottom and some energy is wasted in overcoming the resistance force by air.
Potential Energy = Kinetic energy + Energy to overcome resistance.
⇒ Kinetic energy = Potential Energy - Energy to overcome resistance.
Energy to overcome resistance force is the work done by the wrench against the resistance force and is given as:
Therefore, Kinetic energy at the bottom is given as:
Hence, the kinetic energy of the wrench be when it hits the water is 1425.11 J.
Answer:
a) see attached, a = g sin θ
b)
c) v = √(2gL (1-cos θ))
Explanation:
In the attached we can see the forces on the sphere, which are the attention of the bar that is perpendicular to the movement and the weight of the sphere that is vertical at all times. To solve this problem, a reference system is created with one axis parallel to the bar and the other perpendicular to the rod, the weight of decomposing in this reference system and the linear acceleration is given by
Wₓ = m a
W sin θ = m a
a = g sin θ
b) The diagram is the same, the only thing that changes is the angle that is less
θ' = 9/2 θ
c) At this point the weight and the force of the bar are in the same line of action, so that at linear acceleration it is zero, even when the pendulum has velocity v, so it follows its path.
The easiest way to find linear speed is to use conservation of energy
Highest point
Em₀ = mg h = mg L (1-cos tea)
Lowest point
Emf = K = ½ m v²
Em₀ = Emf
g L (1-cos θ) = v² / 2
v = √(2gL (1-cos θ))
1. Always be the bigger person
2. Violence is never the answer
3. Don’t fight fire with fire
Answer:
a) <em>8.33 x 10^-6 Pa</em>
b) <em>8.23 x 10^-11 atm</em>
c) <em>1.67 x 10^-5 Pa</em>
d) <em>1.65 x 10^-10 atm</em>
<em></em>
Explanation:
Intensity of the light 
= 2500 W/m^2
speed of light 
<u> </u>= 3 x 10^8 m/s
a) we know that the pressure for for a totally absorbing surface is given as
= 
= 2500/(3 x 10^8) = <em>8.33 x 10^-6 Pa</em>
b) 1 atm = 101325 Pa
= (8.33 x 10^-6)/101325 = <em>8.23 x 10^-11 atm</em>
c) for a totally reflecting surface
= 
= twice the value for totally absorbing
= 2 x 8.33 x 10^-6 = <em>1.67 x 10^-5 Pa</em>
d) 1 atm = 101325 Pa
= 2 x 8.23 x 10^-11 = <em>1.65 x 10^-10 atm</em>
Efficiency of heat engine is determined by the ratio of difference in temperature of cold from hot reservoir to the temperature of hot reservoir over temperature of hot reservoir.
Answer: Option A
<u>Explanation:</u>
Efficiency is defined as the output from the input. So it is the ratio of energy output to the energy input. In case of temperature, it is the change in temperature from hot reservoir to cold reservoir with the overall hot reservoir temperature.
Thus, option A is the most suitable as the heat will be transferred from high temperature to low temperature. So the hot reservoir will be releasing the energy. So the conversion of hot reservoir temperature to cool reservoir temperature is defined as the efficiency. Thus, option A is the most suitable.
