The answer is B. On a sunny day, the air over a lake will be cooler than the air over the bordering land.
        
                    
             
        
        
        
Upthrust is the upward force exerted by fluids on the surface of an object immersed in fluids. Thrust:- It is the force acting perpendicular to the surface. Upthrust:- It is the upward force exerted by the fluid on the surface of an object immersed in liquid.
I hope it's help you
 
        
             
        
        
        
Answer:
400 W/m^2 and 31℃
Explanation:
The output heat flux q"= 20 W/m^2 (geven)
The output heat flux from.the wall to the air by convection 
q"conv = h(ts - t∞)
q"conv = 20(50-30) = 400 W/m^2
 Therefor, this case is unsteady and the wall temperature changes with time till the energy balance exist.
ENERGY BALANCE
The input energy must be equal to the output energy for steady state condition. If not the state will be unstaidy or transient.
2. Its noticed that the output heat flux is not that the I put heat flux, therefore the wall tempers will be decreased till the output heat flux is reduced to the value of the given input heat flux
 
 T steady = T∞ +q"/h
 = 30 + 20/20 = 31℃
 
        
             
        
        
        
Answer:
Inertia
Explanation:
Your body is naturally resisting turning left, as it wants to continue straight. So if feels like you are going right.
 
        
                    
             
        
        
        
The red box must way more. Gravitational potential energy is the product of a an objects mass times the acceleration due to gravity (which is constant on earth) times its height. Since the objects are on the same shelf they are at the same height, and since gravitational acceleration is constant as long as we stay on planet earth, then the mass is the only possible thing that could have changed. This means that the red box must weigh more than the blue box.