Answer:
(a) -472.305  J
(b) 1 m
Explanation:
(a)
Change in mechanical energy equals change in kinetic energy
Kinetic energy is given by
Initial kinetic energy is 
Since he finally comes to rest, final kinetic energy is zero because the final velocity is zero
Change in kinetic energy is given by final kinetic energy- initial kinetic energy hence
0-472.305  J=-472.305  J
(b)
From fundamental kinematic equation

Where v and u are final and initial velocities respectively, a is acceleration, s is distance
Making s the subject we obtain
 but a=\mu g hence
 but a=\mu g hence

 
        
             
        
        
        
the determination of the age or date of organic matter from the relative proportions of the carbon isotopes carbon-12 and carbon-14 that it contains. The ratio between them changes as radioactive carbon-14 decays and is not replaced by exchange with the atmosphere.
 
        
             
        
        
        
The volume of the rod is 1.26×10⁻⁵ m³, and the linear charge density of the rod is 3.64 C/m
<h3>What is volume?:</h3>
This is the product of the height of a solid object and its crossectional area.
The Volume of the rod is can be calculated using the formula below.
Note: A rod has the shape of a cylinder.
Formula:
- V = πr²h............... Equation 1
Where:
- V = Volume of the rod
- r = radius of the rod
- h = height of the rod.
From the question,
Given:
- r = 4mm = 0.004 m
- h = 25 cm = 0.25 m
- π = 3.14
Substitute these values into equation 1
- V = 3.14(0.004²)(0.25)
- V = 1.26×10⁻⁵ m³
<h3>What is linear charge density:</h3>
This is the ratio of the charge on an object to the length of the object.
The linear charge density of the rod can be calculated using the formula below.
- D = Q/h.................... Equation 2
Where:
- D = Linear charge density of the rod
- Q = Charge on the rod.
- h = height or length of the rod
From the question
Given:
- Q = 0.91 C
- h = 25 cm = 0.25 m
Substitute these values into equation 2
- D = 0.91/0.25
- D = 3.64 C/m
Hence, The volume of the rod is 1.26×10⁻⁵ m³, and the linear charge density of the rod is 3.64 C/m
Learn more about charge density here: brainly.com/question/14568868
 
        
             
        
        
        
Answer:
I think its C All visible light wavelengths (ROYGBV) are absorbed by the board
 
        
             
        
        
        
Answer: 2.70 cm
Given:
Density, 
Mass, m=184 g
Formula Used:
Volume, V = density/mass
 where a is the side of the cube
 where a is the side of the cube 

hence, the length of one side of silver cube is 2.70 cm