Answer: 114 km/h
Explanation:
The formula for determining average speed is expressed as 
Average speed = total distance/total time
The car travels 85 km in the first half hour of a trip. The car continues to travel for 2 more hours and travels 200 km. It means that the total distance that the car travels is 
85 + 200 = 285 km
The total time spent by the car is 
0.5 + 2 = 2.5 hours
Therefore,
Average speed = 285/2.5 = 114 km/h
 
        
             
        
        
        
Answer:
54.6°
Explanation:
From law of reflection i=r. 
So, construct the reflected ray at 55.7°degrees from the normal and let it fall on the other mirror.  
Now draw the second normal at the point of incidence and again measure the angle of incidence, and draw the angle of reflection. 
If you consider triangle AOB, one angle is ∠AOB=90°
  and ∠OAB is 54.6°
  
From angle sum property third angle ie ∠ABO=180°-90°-54.6°=35.4°
  
So, the second incident angle will be 54.6°
Hence, the second reflected angle will be 54.6 degrees.
 
        
             
        
        
        
Answer:
 62.8 μC
Explanation:
Here is the complete question
The volume electric charge density of a solid sphere is given by the following equation: ρ = (0.2 mC/m⁵)r²The variable r denotes the distance from the center of the sphere, in spherical coordinates. What is the net electric charge (in μC) of the sphere if the radius of the sphere is 0.5 m?
Solution
The total charge on the sphere Q = ∫∫∫ρdV where ρ = volume charge density = 0.2r² and dV = volume element in spherical coordinates = r²sinθdθdrdΦ
So,  Q =  ∫∫∫ρdV 
Q =  ∫∫∫ρr²sinθdθdrdΦ
Q =  ∫∫∫(0.2r²)r²sinθdθdrdΦ
Q =  ∫∫∫0.2r⁴sinθdθdrdΦ
We integrate from r = 0 to r = 0.5 m, θ = 0 to π and Φ = 0 to 2π
So, Q =  ∫∫∫0.2r⁴sinθdθdrdΦ
Q =  ∫∫∫0.2r⁴[∫sinθdθ]drdΦ
Q =  ∫∫0.2r⁴[-cosθ]drdΦ
Q =  ∫∫0.2r⁴-[cosπ - cos0]drdΦ
Q =  ∫∫∫0.2r⁴-[-1 - 1]drdΦ
Q =  ∫∫0.2r⁴-[- 2]drdΦ
Q =  ∫∫0.2r⁴(2)drdΦ
Q =  ∫∫0.4r⁴drdΦ
Q =  ∫0.4r⁴dr∫dΦ
Q =  ∫0.4r⁴dr[Φ]
Q =  ∫0.4r⁴dr[2π - 0]
Q =  ∫0.4r⁴dr[2π]
Q =  ∫0.8πr⁴dr
Q =  0.8π∫r⁴dr
Q =  0.8π[r⁵/5]
Q = 0.8π[(0.5 m)⁵/5 - (0 m)⁵/5] 
Q = 0.8π[0.125 m⁵/5 - 0 m⁵/5]
Q = 0.8π[0.025 m⁵ - 0 m⁵]
Q = 0.8π[0.025 m⁵]
Q = (0.02π mC/m⁵) m⁵
Q = 0.0628 mC
Q = 0.0628 × 10⁻³ C
Q = 62.8 × 10⁻³ × 10⁻³ C
Q = 62.8 × 10⁻⁶ C
Q = 62.8 μC
 
        
             
        
        
        
C. 
Explanation: ionic compounds are metals and nonmetals, refer to your periodic table