You have a meter stick marked to the nearest millimeter. Which of these measurements is written with the correct amount of preci
2 answers:
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Answer:
Time taken = 10400 s
Explanation:
Given:
Initial speed of the train,
Final speed of the train,
Displacement of the train,
Using Newton's equation of motion,
Now, using Newton's equation of motion for displacement,
Now, plug in the value of in the above equation. This gives,
Now, plug in 234000 m for , 25 m/s for
and 20 m/s for
. Solve for
.
Therefore, the time taken by the train is 10400 s.
Answer: 2. Solution A attains a higher temperature.
Explanation: Specific heat simply means, that amount of heat which is when supplied to a unit mass of a substance will raise its temperature by 1°C.
In the given situation we have equal masses of two solutions A & B, out of which A has lower specific heat which means that a unit mass of solution A requires lesser energy to raise its temperature by 1°C than the solution B.
Since, the masses of both the solutions are same and equal heat is supplied to both, the proportional condition will follow.
<em>We have a formula for such condition,</em>
.....................................(1)
where:
= temperature difference
- Q= heat energy
- m= mass of the body
- c= specific heat of the body
<u>Proving mathematically:</u>
<em>According to the given conditions</em>
- we have equal masses of two solutions A & B, i.e.
- equal heat is supplied to both the solutions, i.e.
- specific heat of solution A,
- specific heat of solution B,
&
are the change in temperatures of the respective solutions.
Now, putting the above values
Which proves that solution A attains a higher temperature than solution B.