Answer:
 it's A
Explanation:
wen aligning the vectors the head and the tail should meet
 
        
             
        
        
        
Answer:
Explanation:
the force that you applied caused the notebook to move.
the force applied on the notebook by the table causes it to stop moving.
this is because after sometime the book uses up the force and later the force you applied is less than that of the force by the table.
 
        
             
        
        
        
We will convert the 1dm3 in terms of cm3 as follows:
1dm^3 = (10 cm)^3
= 1000 cm^3
The mass of platinum is equal to 900 lb. 
Then we will convert the mass in terms of grams as follows:
1 lb = 453.6 g
900 = 900 x 453.6 g
= 408240 g
Then density of platinum is equal to 21.4 g/cm^3 
We will calculate the volume of platinum in mass 408240 g as follows:
Volume of platinum = mass of platinum / density of platinum
= 408240 g / 21.4 g/cm^3 
= 19076.6 cm^3  
The total volume of platinum is 19076.6 cm^3
The volume of platinum in 1 L bar is 1000cm^3
So, to calculate the number of bars we will use the formula as follows;
Number of bars = volume of platinum available / volume of platinum required in 1 L bar
= 19076.6 cm^3 / 1000 cm^3
= 19
So, the number of bars are 19.
        
             
        
        
        
Answer:
The wavelength of the light is  .
.
Explanation:
Given that,
Distance between the slit centers d= 1.2 mm
Distance between constructive fringes 
Distance between fringe and screen D= 5 m
We need to calculate the wavelength 
Using formula of width

Put the value into the formula




Hence, The wavelength of the light is  .
.
 
        
             
        
        
        
Answer:

Explanation:
Given that
The speed of the airplane ,v= 142 m/s
The speed of the air ,u = 30 m/s
Lets take angle make by airplane from east direction towards north direction is θ .
Now by using diagram ,we can say that

Now by putting the values in the above equation we get



Therefore the angle will be 12.19° .