Answer: Smoking cigarettes
Explanation: The other options don't cause pollution to form in the air besides smoking, from the particles it creates causing harm and damage to your lungs and fill the air with smoke particles.
 
        
                    
             
        
        
        
Formula for time
t=d/s
so…
t= 48m/4m/s
the two ms cancel each other out and ur left with s
t=12s
        
             
        
        
        
The significant figures also known as the significant digits or precision of a number written in positional notation are digits that carry meaningful contributions to its measurements
        
             
        
        
        
Answer:
Angular velocity, 
Explanation:
It is given that,
Maximum emf generated in the coil, 
Diameter of the coil, d = 40 cm
Radius of the coil, r = 20 cm = 0.2 m
Number of turns in the coil, N = 500
Magnetic field in the coil, 
The angle between the area vector and the magnet field vector varies from 0 to 2 π radians. The formula for the maximum emf generated in the coil is given by :




So, the angular velocity of the circular coil is 35.36 rad/s. Hence, this is the required solution.
 
        
             
        
        
        
Answer:

Explanation:
By conservation of the linear momentum:
m1*V1 = (m1+m2)*V2
Solving for V2:

The kinetic energies are:



Simplifying:

The ratio will be:

