Answer:
25 degrees
Explanation:
The angle of incidence equals the angle of reflection
 
        
             
        
        
        
Let, 1st force = a
2nd force = b
A.T.Q,
a+b = 10
a-b = 6
Calculate for a & b, you'll get a=8 & b= 2
After increasing by 3, it'll be a = 8+3 = 11 & b=2+3 = 5
Resultant force at 90 degree angle = 11+5 = 16 Newtons
 
        
                    
             
        
        
        
1.  D - sound travels the fastest through solids
2. 50 mm/s - v=fa
3. B - only process that involves changing waves
 
        
             
        
        
        
Since car is initially at rest so at that position the net force on car in vertical as well as horizontal both direction is zero
but after lights are green the car will speed up in horizontal direction
so now we can say that
It will accelerate in horizontal direction
So now as per Newton's formula we have

so now the force in horizontal direction will become nonzero while in vertical direction car is still in equilibrium
So now we can say


so the correct answer will be
 C. The net force on the car is greater than zero in the horizontal direction.