Answer:
96 Joules
Explanation:
The formula for work is Fnet times displacement (F x d = w) which, in this case, 48N is the Fnet and 2m as the displacement. Then all we need to do is multiply these two and we get 96 Joules. 
 
        
             
        
        
        
Answer:
Explanation:
We shall apply Stefan's formula 
E = AσT⁴
When T = 300
I₁ = Aσ x 300⁴
When T = 400K 
I₂ = Aσ x 400⁴
I₂ / I₁ = 400⁴ / 300⁴
= 256 / 81
= 3.16 
I₂ = 3.16 I₁ . 
 
        
             
        
        
        
Do u know Chinese ?if yes I can explain to u easily 
        
             
        
        
        
Answer:
Explanation:
Actual weight, Wo = 5 N 
Apparent weight, W = 4.5 N 
density of water = 1 g/cm^3 = 1000 kg/m^3
density of gold, = 19.32 g/cm^3 = 19.32 x 1000 kg/m^3
Buoyant force = Actual weight - Apparent weight 
Volume x density of water x g = 5 - 4.5 
V x 1000 x 9.8 = 0.5 
V = 5.1 x 10^-6 m^3 
Weight of gold = Volume of gold x density of gold x gravity 
W' = 5.1 x 10^-6 x 19.32 x 1000 x 9.8 = 0.966 N 
As W' is less than W so, it is not pure gold. 
 
        
             
        
        
        
Well i honestly wouldn’t know