Which of these statements are true...
I think (1)and (5) are correct
1)A reversing vehicle must have negative velocity
2) A stationary object must have zero position
3)Two vehicles trvelling at the same speed at the same instant of time on the same road must have the same velocity.
4) If a vehicle has zero acceleration it must be stationary
5) Velocity is the rate of change of position
6)An object slowing down must have negative velocity
7)The graph of position against time for a vehicle with constant velocity is a straight line
I appreciate your help :- Thanks
Well, seven is certainly true. Five is true. But 1) does not make sense. If it reverses, the final velocity is in the opposite direction as the initial velocity. So on the term "negative velocity", you can decide what it means. The initial velocity can be a postive or negative quantity, and the final velocity will be opposite to the intial. The wording is silly on that choice.
Bob
thanks..
To determine which statements are true, let's analyze each statement one by one:
1) A reversing vehicle must have negative velocity.
This statement is true. Velocity is defined as the rate at which an object's position changes with respect to time, and if a vehicle is reversing, its position is decreasing, hence its velocity is negative.
2) A stationary object must have zero position.
This statement is not necessarily true. A stationary object means that its velocity is zero, indicating that it is not changing its position. However, the object's position could be any value, positive or negative, as long as it remains constant.
3) Two vehicles traveling at the same speed at the same instant of time on the same road must have the same velocity.
This statement is true. Velocity is dependent on both speed and direction. If two vehicles are traveling at the same speed, it means they are covering the same amount of distance in the same unit of time. If they are on the same road, they must be going in the same direction, hence their velocities are equal.
4) If a vehicle has zero acceleration, it must be stationary.
This statement is true. Acceleration is defined as the rate at which velocity changes with respect to time. If a vehicle has zero acceleration, it means its velocity is not changing, and hence it is not accelerating. Therefore, if its initial state is stationary, it remains stationary.
5) Velocity is the rate of change of position.
This statement is true. Velocity is defined as the rate at which an object's position changes with respect to time. It represents how fast an object is moving and in which direction.
6) An object slowing down must have negative velocity.
This statement is not necessarily true. While an object slowing down does indicate its velocity is decreasing, it doesn't inherently mean it has negative velocity. It could be moving in a positive direction and slowing down, resulting in positive but decreasing velocity.
7) The graph of position against time for a vehicle with constant velocity is a straight line.
This statement is true. If a vehicle has constant velocity, it means it is moving at a steady speed in a straight line without changing its direction. On a position-time graph, this would be represented as a straight line with a constant slope.
Based on the analysis above, statements 1, 3, 4, and 5 are true.