If the speedometer of your car reads a constant speed of 40 km/hr, can you say 100% for sure that the car has a constant velocity? Explain your answer.
The correct answer and explanation is:
The answer is no. You cannot say 100% for sure that the car has a constant velocity just because the speedometer reads a constant speed of 40 km/hr.
Explanation:
Speed and velocity are related but not the same. Speed is a scalar quantity, meaning it only refers to how fast an object is moving, without regard to direction. In contrast, velocity is a vector quantity, which means it not only considers the speed but also the direction in which the object is moving.
When a car’s speedometer reads a constant speed of 40 km/hr, it tells you that the car is moving at that rate. However, the speedometer does not provide any information about the direction of the car’s motion. The car could be changing direction while maintaining a constant speed. For example, if the car is going around a curve at 40 km/hr, its speed remains constant, but its direction changes, so its velocity is not constant.
In order for the velocity to be constant, the car must maintain both a constant speed and a constant direction. If the car is traveling in a straight line at 40 km/hr, then it would have a constant velocity. However, if the car is moving in a curved or circular path, even if the speed is constant, the velocity will not be constant because the direction of motion is continuously changing.
To summarize, a constant speed on the speedometer does not guarantee constant velocity unless the direction of motion remains unchanged as well. Therefore, the car could be changing its direction while maintaining the same speed, meaning the velocity is not constant.