Explanation:
"The burning of fossil fuels , oil and natural and power from nuclear power provide about 87% of the energy used in the world. 
Coal, natural gas, petroleum and nuclear power are the major energy providers to the whole world. Till date we are heavily depend on them. They provide for about 87% of the total energy used in the world. 
 
        
             
        
        
        
Answer:
The gravitational acceleration of the planet is, g = 8 m/s²
Explanation:
Given data,
The distance the object falls, s = 144 m
The time taken by the object is, t = 6 s
Using the III equations of motion
                   S = ut + ½ gt²
∴                 g = 2S/t²
Substituting the given values,
                    g = 2 x 144 /6²
                       = 8 m/s² 
Hence, the gravitational acceleration of the planet is, g = 8 m/s² 
 
        
             
        
        
        
The expansion of the observable universe began <span>with the explosion of a single particle at a definite point in time.</span>
        
             
        
        
        
Average speed = (distance covered) / (time to cover the distance)
Average speed = (4 meters) / (5 seconds)
Average speed = (4/5) (meters/seconds)
Average speed = 0.8 m/s