PYQ - Velocity — task. Physics CBSE Live product, Class 9.

Give a long answer to the question given below.

When something moves, its position keeps changing. We use average velocity to describe how quickly and in what direction that position changes it's the displacement over time. On the other hand, average speed is all about how fast something moves along its path total distance over time.

a. A \(250 meter\) long train is moving steadily at \(45\ \frac{km}{h}\). How many \(seconds\) will it take for the entire train to cross a bridge that's \(750\ meters\) long?

b. A cyclist is riding around a circular track with a radius of \(40\ meters\) and takes \(40\ seconds\) to go halfway around. What is the cyclist’s average velocity during this half-turn?

a. The formula to calculate the time is

\(Time\ =\ \frac{Velocity}{Distance}\)
\(Time\ =\ \frac{Displacement}{Velocity}\)
\(Time\ =\ Distance \times Velocity\)
\(None\ of\ these\)

The duration for the train to cross a \(750\ meter\) long bridge is

\(60\ s\)
\(88\ s\)
\(80\ s\)
\(20\ s\)

b. The formula to caluculate the average velocity is

\(Average\ velocity\ =\ \frac{Total displacement}{Total time}\)
\(Average\ velocity\ =\ {total distance} \times {Total time}\)
\(Average\ velocity\ =\ {Total displacement} \times {Total time}\)
\(Average\ velocity\ =\ \frac{Total distance}{Time}\)

The average velocity in half revolution is

\(1\ m/s\)
\(0.5\ m/s\)
\(4\ m/s\)
\(2\ m/s\)

6. PYQ - Velocity

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