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. 

S.I. unit of time is second.

• A speed-time graph shows how speed changes over time.
• In uniform motion, the speed remains constant.
• This means that when you plot speed against time, the graph is a straight horizontal line.
• A straight line indicates no change in speed, which is characteristic of uniform motion.
• In contrast, non-uniform, discontinuous, or accelerated motions would show curves or slopes on the graph.

- Velocity is the correct answer.
- It represents the rate at which an object changes its position in a specific direction
- Velocity is a vector quantity, meaning it has both magnitude (speed) and direction.
- It indicates how fast an object is moving and in which direction.
- Unlike speed, which is scalar and only measures how fast something moves, velocity specifically accounts for direction, making it crucial for describing motion in physics accurately.

 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.

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