Answer:
The students conclusion is wrong.
Explanation:
The students conclusion is wrong because liquids can not soak into concrete. The water evaporated because it was a hot sunny day. The water turned into a gas called water vapor.
 
        
             
        
        
        
The solution for this problem is computed by through this formula, F = kQq / d²Plugging in the given values above, we can now compute for the answer.
F = 8.98755e9N·m²/C² * -(7e-6C)² / (0.03m)² = -489N, the negative sign denotes attraction.
        
             
        
        
        
Answer: B. the isovolumetric process 
Explanation: 
In the graph given, the volume is constant throughout. It represents a constant volume process. Such processes are called the isovolumetric process or isochoric process. 
<em>Hence, option B is the correct answer.</em>
Option A is incorrect because in an isobaric process, the pressure is constant.
Option C is incorrect because in an isothermal process, the temperature is constant.
Option D is incorrect because in an adiabatic process there is no heat transfer.
 
        
             
        
        
        
<h3><u>Answer;</u></h3>
Mechanical advantage 
<h3><u>Explanation;</u></h3>
- Mechanical advantage is the ratio of force output from a machine divided by the force input into the machine.
- Mechanical advantage measures the machine's force-magnifying effect. It is an advantage gained by using simple machines to accomplish work with less effort.
- The formula is; M.A = output force/ Input force
 
        
        
        
Answer:
Explanation:
a ) Conservation of momentum is followed 
m₁ v₁  = m₂ v₂
3m x 2 = m  v
v = 6 m/s 
Total kinetic energy 
= 1/2 x .35 x 6 ² + 1/2 x 1.05 x 2 ²
 = 8.4 J
This energy must be stored as elastic energy in the spring which was released as kinetic energy on burning the cord. 
Yes , the conservation of momentum will be followed  in the bursting apart process. Only internal forces have been involved in the process. Two equal and opposite internal forces are created by spring which creates motion and generates kinetic energy.