Answer:
- 3 cm 
Explanation:
From the mirror formula;
1/f = 1/v + 1/u ; where f is the focal length, v is the image distance, and u is the object distance.
1/-4.5 = 1/9 + 1/v 
1/v = -1/4.5 - 1/9
     = -1/3
Therefore; 
v = -3 cm 
Hence; 
Image distance is - 3cm
 
        
             
        
        
        
Hello there! 
I hope you and your family are staying safe and healthy during this unprecendented time. 
A) What is the work done? 
Answer: We need to use the formula 



B) What is the work done on the cart by the gravitational force?  
Alright, we know that the gravitional force is perpendicular to the diplacement. Therefore, we gonna use the following formula: 


C) What is the work done on the cart by the shopper? 
This is the easier part, since we already know that the work done by the shopper is the same as the work done by the friction force 

D) Find the force the shopper exerts, using energy considerations. 

E) What is the total work done? 
You just need to add them: 

 
        
             
        
        
        
In order to draw the free body diagram, first let's calculate the friction force acting on the crate:

Since the friction force is greater than the force applied, the crate will not move, and the friction force will be equal to the force applied.
The weight force is equal to 40 * 9.8 = 392 N.
So, drawing the diagram, we have:
 
        
             
        
        
        
In order to increase muscular endurance, it is important to take part in activities that increase the size of muscle cells and the amount of blood that is delivered to the cells<span>. The increased size of the muscle cells reuires them to contract less to accomplish the same task; moreover, the increased blood flow helps deliver oxygen and nutrients to the blood.</span>
        
                    
             
        
        
        
Answer:
d ) is the answer. 
Explanation:
Let M be the mass  and R be the radius of each of ball , hoop and disc. 
kinetic energy of sphere - 1/2 MV² + 1/2 I ω² ,ω is angular velocity and 
V = ωR
kinetic energy of sphere - 1/2 MV² + 1/2 x 2/5 MR² ω²
= 1/2 MV² + 1/5 MR² ω²
MV² ( 1/2 + 1/5 ) 
= .7 MV²
kinetic energy of Disk - 1/2 MV² + 1/2 I ω² ,ω is angular velocity and 
V = ωR
kinetic energy of Disk - 1/2 MV² + 1/2 x 1/2 MR² ω²
= 1/2 MV² + 1/4 MR² ω²
MV² ( 1/2 + 1/4 ) 
= .75 MV²
kinetic energy of Hoop - 1/2 MV² + 1/2 I ω² ,ω is angular velocity and 
V = ωR
kinetic energy of hoop - 1/2 MV² + 1/2  MR² ω²
= 1/2 MV² + 1/2 MR² ω²
MV² ( 1/2 + 1/2 ) 
=  MV²
Kinetic energy is largest in case of hoop and least in case of sphere . So hoop will go up to the highest point and sphere will go to a height which will be least among the three.