Answer:
The final speed of the crate is 12.07 m/s.
Explanation:
For the first 10.0 meters, the only force acting on the crate is 225 N, so we can calculate the acceleration as follows:


Now, we can calculate the final speed of the crate at the end of 10.0 m:
For the next 10.5 meters we have frictional force:


So, the acceleration is:
The final speed of the crate at the end of 10.0 m will be the initial speed of the following 10.5 meters, so:
Therefore, the final speed of the crate after being pulled these 20.5 meters is 12.07 m/s.
I hope it helps you!
Answer:
q₃=5.3nC
Explanation:
First, we have to calculate the force exerted by the charges q₁ and q₂. To do this, we use the Coulomb's Law:

Since we know the net force, we can use this to calculate q₃. As q₁ is at the right side of q₃ and q₁ and q₃ have opposite signs, the force F₁₃ points to the right. In a similar way, as q₂ is at the left side of q₃, and q₂ and q₃ have equal signs, the force F₂₃ points to the right. That means that the resultant net force is the sum of these two forces:

In words, the value of q₃ must be 5.3nC.
Answer: condensation process is exothermic. The correct option is IV.
Explanation: Exothermic reaction is a chemical reaction in which heat is released to the surrounding environment.
condensation is defined as a process by which a medium changes from gaseous phase into liquid phase. Using water molecules to illustrate, to transform water molecules to gaseous phase it requires the heat of vaporization to be overcomed. This same hear of vaporization needs to be given off when changing back to liquid phase.