Answer:


Explanation:
Let the mass of the other car is "m" and its kinetic energy is

now the mass of the first car is two and half times and its kinetic energy is half that of other car
so we will have



now speed of both cars is increased by value of 9 m/s
so now we will have same kinetic energy for both cars





so speed of first car is


Highest frequency EM waves: cosmic rays and gama rays
Lowest frequency EM waves:
Radio and Tv waves
Heat transferred - Work done = Internal Energy
Explanation:
- If there is more heat transfer than the work done, the energy difference is called internal energy
- The first law of thermodynamics equation is given as ΔU=Q−W where, ΔU = Internal energy; Q = Heat transfer; W = Work done
- Heat = transfer of thermal energy between two bodies at different temperatures
- Work = force used to transfer energy between a system and its surroundings
- The First Law of Thermodynamics states - energy can be converted from one form to another with the interaction of heat, work and internal energy
- Energy cannot be created nor destroyed
<h2>Answer:</h2>
A series circuit occurs when the elements are connected along a simple path so the same current flows through all the elements. On the other hand, a parallel circuit occurs when there are two or more paths for the electricity to flow. The diagram are shown in the Figure below. We have chosen a source and resistors to illustrate this problem.
Answer:at 21.6 min they were separated by 12 km
Explanation:
We can consider the next diagram
B2------15km/h------->Dock
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B1 at 20km/h
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V
So by the time B1 leaves, being B2 traveling at constant 15km/h and getting to the dock one hour later means it was at 15km from the dock, the other boat, B1 is at a distance at a given time, considering constant speed of 20km/h*t going south, where t is in hours, meanwhile from the dock the B2 is at a distance of (15km-15km/h*t), t=0, when it is 8pm.
Then we have a right triangle and the distance from boat B1 to boat B2, can be measured as the square root of (15-15*t)^2 +(20*t)^2. We are looking for a minimum, then we have to find the derivative with respect to t. This is 5*(25*t-9)/(sqrt(25*t^2-18*t+9)), this derivative is zero at t=9/25=0,36 h = 21.6 min, now to be sure it is a minimum we apply the second derivative criteria that states that if the second derivative at the given critical point is positive it means here we have a minimum, and by calculating the second derivative we find it is 720/(25 t^2 - 18 t + 9)^(3/2) that is positive at t=9/25, then we have our answer. And besides replacing the value of t we get the distance is 12 km.