Answer:
The deceleration is   
  
Explanation:
From the question we are told that 
   The distance of the car from the crossing is 
    The speed is 
     The reaction time of the engineer is  
Generally the distance covered during the reaction time is  
       
=>   
=>   
Generally distance of the car from the crossing after the  engineer reacts is 
        
        
=>  
      
=> 
Generally from kinematic equation 
       
Here v is the final velocity of the car which is  0 m/s 
So 
         
=>     
  
 
        
             
        
        
        
Answer:
The tunnel probability for 0.5 nm and 1.00 nm are   and
 and  respectively.
 respectively.
Explanation:
Given that,
Energy E = 2 eV
Barrier V₀= 5.0 eV
Width = 1.00 nm
We need to calculate the value of 
Using formula of 

Put the value into the formula


(a). We need to calculate the tunnel probability for width 0.5 nm
Using formula of tunnel barrier 

Put the value into the formula


(b). We need to calculate the tunnel probability for width 1.00 nm


Hence, The tunnel probability for 0.5 nm and 1.00 nm are   and
 and  respectively.
 respectively.
 
        
             
        
        
        
Answer:
d = 1.047 mm
Explanation:
given,
diameter of the wire = 2.0-cm
length of solenoid = 15 cm = 0.15
Current in the wire = I = 2.5 A
magnetic field = B = 3.0 mT
Magnetic field inside the solenoid
         
         
                N x d = l
          
 
         
         
         
         
                d = 1.047 x 10⁻³ m
                d = 1.047 mm
diameter of the wire is d = 1.047 mm
 
        
             
        
        
        
Answer:
The average force exerted by the water on the ground is 17.53 N.
Explanation:
Given;
mass flow rate of the water, m' = 135 kg/min
height of fall of the water, h = 3.1 m
the time taken for the water to fall to the ground;

mass of the water;

the average force exerted by the water on the ground;
F = mg
F = 1.789 x 9.8
F = 17.53 N
Therefore, the average force exerted by the water on the ground is 17.53 N.
 
        
             
        
        
        
Answer:
Explanation:
Given
magnitude of vector=8.7 m/s
Direction 
Therefore vector x component is 
=-2.104 
i.e. it is acting in negative x axis
vector y component
Therefore it lies in negative y axis
Judging vector x and y component
It lies in third quadrant