Test: Motion & Time - UPSC MCQ

• Motion refers to the change in position of an object over time.
• It occurs when an object moves from one location to another relative to a reference point or its surroundings.
• Common examples include a car driving down a road, a person walking, or a bird flying.
• Acceleration, momentum, and force are related concepts but do not specifically define the change in position itself.

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

• The speedometer is a device found in vehicles that measures the current speed of the vehicle.
• It provides real-time information, allowing drivers to maintain safe speeds and abide by traffic regulations.
• Unlike an odometer, which measures distance traveled, the speedometer focuses solely on speed.
• Ammeter and voltmeter measure electrical current and voltage, respectively, and are not related to vehicle speed.

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