Measuring speed

We are given distance = 200 m and time = 40 s. Both are already in standard units, so no conversion is needed.

Using the formula: $\text{speed}=\frac{\text{distance}}{\text{time}}=\frac{200}{40}=5\text{ m/s}$

The average speed is 5 m/s. Always include the unit (m/s) to gain full marks.

We need to find speed using distance = 200 m and time = 40 s. The correct formula is $\text{speed}=\frac{\text{distance}}{\text{time}}$.

160 m/s would come from multiplying 200 × 40 = 8000... wait, that is not 160 either — 160 could come from 200 − 40. Neither operation is correct for speed. Eliminate.

0.2 m/s would come from dividing time by distance: $\frac{40}{200}=0.2$. This is the formula inverted, which is wrong. Eliminate.

8 m/s does not result from any correct calculation with these numbers. $\frac{200}{40}=5$, not 8. Eliminate.

$\frac{200}{40}=5$, so 5 m/s is correct.

Instantaneous speed is the speed of an object at one specific moment in time. It does not consider any period of time — just a single instant.

A car's speedometer continuously updates to show how fast the car is moving right now — at this exact moment. This is a classic real-world example of instantaneous speed.

The answer is 'The speed shown on a car's speedometer at a given moment' — this directly matches the definition of instantaneous speed.

We need to find which option describes instantaneous speed — speed at a single moment, not averaged over time.

Total distance ÷ total time describes average speed, not instantaneous speed. Eliminate.

Timing a fixed distance gives you the average speed over that distance — it still covers a period of time. Eliminate.

Averaging repeated measurements improves reliability of a speed estimate — but the result is still an average, not instantaneous. Eliminate.

The speedometer reading at a given moment is the only option describing speed at one specific instant — this is instantaneous speed.