Test: Motion & Time - UPSC MCQ

Change in position of a body with respect to its surrounding is called as motion.

Sundials were used for measuring time in earlier days on the basis of shadow position.

The speed of vehicle at particular point of time is recorded by speedometer fitted on the dashboard of vehicle.

The basic unit of distance is metre (m). The basic unit of time is second (s). Since we know that s=d/t. Therefore, the basic unit of speed is m/s.

So option D is the correct answer. 

- A distance-time graph represents how distance changes with time.
- A straight line on a distance-time graph indicates a constant rate of change of distance over time.
- Uniform motion means an object travels equal distances in equal intervals of time.
- Therefore, for uniform motion, a distance-time graph is a straight line.
- Non-uniform motion, discontinuous motion, and accelerated motion would result in curves or discontinuities, not straight lines.

 We know , 
1 km=1000m , 1 hour=3600s
1km/h=1000/3600m/s=5/18m/s
72km/h=72×5/18m/s
=4×5m/s
=20m/s.

- The correct instrument used to measure the total distance traveled by a vehicle is the odometer.

- An odometer records the cumulative distance that a vehicle has traveled over its lifetime, usually displayed in miles or kilometers.

- Other instruments mentioned:
- Speedometer: Measures the current speed of the vehicle.
- Thermometer: Measures temperature, not applicable for vehicle distance.
- Barometer: Measures atmospheric pressure, unrelated to vehicle travel.

Thus, option C: Odometer is correct.

Time period = Total time taken/Number of oscillations
= 32s/20
=1.6 s
Time period = 1.6 s