Concrete is formed of sand. Is it incorrect to suggest that some houses are built using concrete blocks?
Answer:
20N
Explanation:
Given parameters:
Force(N) Acceleration(m/s²)
10 0.2
? 0.4
Unknown:
The force applied when the acceleration is 0.4m/s²
Solution:
From newton's second law of motion;
Force = mass x acceleration
Since we are using the same box, let us find the mass of the box;
Force = mass x acceleration
10 = mass x 0.2
mass =
= 50kg
Now,
The force in the second instance will be;
Force = 50 x 0.4 = 20N
This is an incomplete question, here is a complete question.
Calculate the solubility of each of the following compounds in moles per liter. Ignore any acid-base properties.
CaCO₃, Ksp = 8.7 × 10⁻⁹
Answer : The solubility of CaCO₃ is, 
Explanation :
As we know that CaCO₃ dissociates to give
ion and
ion.
The solubility equilibrium reaction will be:

The expression for solubility constant for this reaction will be,
![K_{sp}=[Ca^{2+}][CO_3^{2-}]](https://tex.z-dn.net/?f=K_%7Bsp%7D%3D%5BCa%5E%7B2%2B%7D%5D%5BCO_3%5E%7B2-%7D%5D)
Let solubility of CaCO₃ be, 's'




Therefore, the solubility of CaCO₃ is, 
Answer-The correct option is option d with says all of the above.
Explanation- All three acids that are given combined together to form acid rain in which nitric and sulphuric acid are stronger acids present while carbonic acid is a weaker one.
The carbon dioxide admitted in air combines with water to form carbonic acid and gives a weak acidic nature to rainwater. Pollution in nature makes sulphur and nitrogen present in air react to form the stronger acids responsible for acid rain.
V1M1 = V2M2
<span>V1 × 2.5 = 1 × 0.75,
so V1 = 0.75/2.5
= 0.3 </span>