<h3><u>Answer;</u></h3>
The magnitude of a vector may be positive even if all of its components are negative.
<h3><u>Explanation</u>;</h3>
- Two vectors are equal if they have the same magnitude and the same direction. If two vectors have the same magnitude (size) and the same direction, then we call them equal to each other.
 - A negative vector is a vector that has the opposite direction to the reference positive direction.
 - When vectors are added, we take into account both their magnitudes and directions.
 
 
        
                    
             
        
        
        
Answer:
3.679 × 
Explanation:
Let's assume that average lifespan for normal human being is 70 years.
In 70 years there are 365 days in each year.
70 years = 70 × 365 days
In one day there are 24 hours.
70 years = 70 × 365 × 24 hours
In one hour there are 60 minutes.
70 years = 70 × 365 × 24 × 60 minutes
we estimate an average respiration rate of about 10 breaths per minute. ... (Given)
Thus, for 70 years number of breath are,
n = 70 × 365 × 24 × 60 × 10
n = 3.679 × 
Hence, estimate number of breath over a period of life is 3.679 × 
. 
 
        
             
        
        
        
Answer:

34.46 V/m
Explanation:
 = Vacuum permeability = 
c = Speed of light = 
I = Intensity = 1.575 W/m²
The maximum magnetic field intensity is given by

The magnetic field intensity is 
The maximum electric field intensity is given by

The  electric field intensity is 34.46 V/m
 
        
             
        
        
        
Answer:
v = 24 cm and inverted image
Explanation:
Given that,
The focal length of the object, f = +8 cm
Object distance, u = -12 cm
We need to find the position &nature of the image. Let v be the image distance. Using lens formula to find it :

Put all the values,

So, the image distance from the lens is 24 cm. 
Magnification,

The negative sign of magnification shows that the formed image is inverted.
 
        
             
        
        
        
The crate moves at constant velocity, this means that its acceleration is zero, so the net force acting on the crate is zero (Newton's second law). 
There are only two forces acting on the crate: the force F applied by the worker and the frictional force, acting in the opposite direction: 

, where 

 is the coefficient of friction and 

 is the mass of the crate. Since the net force should be equal to zero, the two forces must have same magnitude, so we have:

And so, this is the force that the worker must apply to the crate.