Answer:
Elastic potential energy, E = 200 J
Explanation:
It is given that,
Spring constant, K = 4 N/m
initial stretching in the spring, x = 5 m
Finally, it is stretched an additional 5 m i.e. x' = 5 m
Let E is the elastic energy in the spring after Varg stretches the spring. it is given by :


E = 200 J
So, the elastic energy in the spring after Varg stretches the spring is 200 J. hence, this is the required solution.
Complete Question
The complete question is shown on the first uploaded image
Answer:
Explanation:
From he question we are told that
The first mass is 
The second mass is 
From the question we can see that at equilibrium the moment about the point where the string holding the bar (where
are hanged ) is attached is zero
Therefore we can say that

Making x the subject of the formula



Looking at the diagram we can see that the tension T on the string holding the bar where
are hanged is as a result of the masses (
)
Also at equilibrium the moment about the point where the string holding the bar (where (
) and
are hanged ) is attached is zero
So basically


Making
subject


Answer:
7
Explanation:
A substance that is neither acidic nor basic is neutral. The pH scale measures how acidic or basic a substance is. The pH scale ranges from 0 to 14. A pH of 7 is neutral.
Answer:
<em>The average speed of the train is 45 km/h</em>
Explanation:
<u>Speed</u>
It's defined as the distance (d) per unit of time (t) traveled by an object. The formula is:

Let's call x the total distance covered by the train. It covered d1=1/3x with a speed of v1=25 km/h. The time taken is calculated solving for t:



Now the rest of the distance:
d2 = x - 1/3x = 2/3x
Was covered at v2=75 km/h. Thus the time taken is:



The total time is:



Simplifying:

The average speed is the total distance divided by the total time:

Simplifying:

The average speed of the train is 45 km/h
Answer:
The correct answer is option D