Answer: Electromagnetic waves are generated by moving electrons. An electron generates an electric field which we can visualize as lines radiating from the electron Figure 10a. If the electron moves, say it vibrates back and forth, then this motion will be transferred to the field lines and they will become wavy Figure 10b.
        
             
        
        
        
The temperature of the gas is 41.3 °C.
Answer:
The temperature of the gas is 41.3 °C.
Explanation:
So on combining the Boyle's and Charles law, we get the ideal law of gas that is PV=nRT. Here P is the pressure, V is the volume, n is the number of moles, R is gas constant and T is the temperature. The SI unit of pressure is atm. So we need to convert 1 Pa to 1 atm, that is 1 Pa = 9.86923×
 atm. Thus, 171000 Pa = 1.6876 atm.
We know that the gas constant R = 0.0821 atmLMol–¹K-¹. Then the volume of the gas is given as 50 L and moles are given as 3.27 moles.
Then substituting all the values in ideal gas equation ,we get
1.6876×50=3.27×0.0821×T
Temperature = 
So the temperature is obtained to be 314.3 K. As 0°C = 273 K, 
Then 314.3 K = 314.3-273 °C=41.3 °C.
Thus, the temperature is 41.3 °C.
 
        
             
        
        
        
Answer:
A
    
 
B
     
C
  
D
   
Explanation:
Considering the first question 
From the question we are told that 
    The spring constant is  
     The potential energy is  
Generally the potential  energy stored in spring  is mathematically represented as   
=>    
  
=>    
  
=>    
  
Considering the second question 
  From the question we are told that 
    The mass of the dart is  m =  0.050 kg
Generally from the law of energy conservation 
          
=>       
=>      
Considering the third  question 
    The height at which the dart was fired horizontally is  
 Generally  from the law of energy conservation
          
Here  KE is kinetic energy of the dart which is mathematical represented as 
      
=>      
=>       
=>       
Considering the fourth question 
Generally the total time of flight of the dart is mathematically represented as 
        
=>     
=>     
Generally the  horizontal distance from the equilibrium position to the ground is  mathematically represented as 
        
=>     
=>     
 
        
             
        
        
        
Answer:
f1 = -3.50 m
Explanation:
For a nearsighted person an object at infinity must be made to  appear  to be at his far point which is 3.50 m away. The image of an object at infinity must be formed on the same side of the lens as the object.
∴ v = -3.5 m
Using mirror formula,
i/f1 = 1/v + 1/u
Where f1 = focal length of the contact lens, v = image distance = -3.5 m, u =         object distance = at infinity(∞) = 1/0
∴ 1/f1 = (1/-3.5) + 1/infinity
   Note that, 1/infinity = 1/(1/0) = 0/1 =0.
∴ 1/f1 = 1/(-3.5) + 0
   1/f1 = 1/(-3.5)
 Solving the equation by finding the inverse of both side of the equation.
  ∴ f1 = -3.50 m
  Therefore a converging lens of focal length  f1 = -3.50 m
 would be needed by the person to see an object at infinity clearly 
 
        
             
        
        
        
Answer:
it will be curved as in deceleration 
Explanation: