Answer: 390, right
explanation: The net force is just the sum of all of these forces acting on an object. ... This equation is the sum of n forces acting on an object. The magnitude of the net force acting on an object is equal to the mass of the object multiplied by the acceleration of the object, as shown in this formula.
 
        
             
        
        
        
The answer to your question is Metal
        
             
        
        
        
Explanation:
Given that,
Initial speed of the sports car, u = 80 km/h = 22.22 m/s
Final speed of the runner, v = 0
Distance covered by the sports car, d = 80 km = 80000 m
Let a is the acceleration of the sports car.  It can be calculated using third equation of motion as :




Value of g, 


Hence, this is required solution.
 
        
             
        
        
        
The wavelength is 2m.
Hence, Option c) 2m is the correct answer
Given that;
Frequency; 
 
Speed; 
Wavelength; 
using the expression for the relations between wavelength, frequency and speed of wave:

Where 
 is wavelength, f is frequency and v is speed.
We substitute our given values into the equation

The wavelength is 2m.
Hence, Option c) 2m is the correct answer.
To learn more about wavelength, click here: brainly.com/question/1347107