Motion：練習問題

Which of the following correctly defines velocity?

The graph below illustrates the velocity of an object over a period of \(10\text{ s}\).

What is the total displacement of the object during this \(10\text{ s}\) interval?

A car travels around a circular track at a constant speed of \(20\text{ m/s}\). It takes \(40\text{ s}\) to complete exactly one full lap.

What are the magnitude of the car's average velocity and its average speed for the complete lap?

A bus travels along a straight route from a bus stop to the next station located \(600\text{ m}\) away. The journey takes \(50\text{ s}\).
Calculate the average speed of the bus.

A motorcycle accelerates uniformly from an initial velocity of \(5.0\text{ m/s}\) to a final velocity of \(23.0\text{ m/s}\) in \(6.0\text{ s}\).
What is the acceleration of the motorcycle?

A cyclist travels a displacement of \(180\text{ m}\) north in a time of \(15\text{ s}\). Calculate the velocity of the cyclist.

A skateboarder moves along a straight path. A velocity–time graph representing the motion shows that the skateboarder maintains a steady velocity of \(5.0\text{ m/s}\) for \(8.0\text{ s}\), and then decelerates uniformly to rest in a further \(4.0\text{ s}\). Calculate the total displacement of the skateboarder.

A remote-controlled car moves in a straight line. It travels \(60\text{ m}\) east in \(12\text{ s}\), remains stationary for \(8\text{ s}\), and then moves a further \(90\text{ m}\) east in \(10\text{ s}\). Calculate the average velocity of the car for the complete \(30\text{ s}\) journey.

A toy train travels on a straight section of track.

a) The train travels a displacement of \(18\text{ m}\) in a time of \(12\text{ s}\). Calculate the velocity of the toy train.
b) The train then travels in the opposite direction along the same straight line for \(6.0\text{ s}\) at a speed of \(1.5\text{ m/s}\). Calculate the magnitude of the displacement for this second journey.
c) Determine the overall displacement of the toy train from its initial starting point.

A skateboarder moves along a straight pavement.

a) In the first part of the motion, the skateboarder moves \(150\text{ m}\) east in \(25\text{ s}\). Calculate the velocity of the skateboarder during this part.
b) The skateboarder turns around and travels \(90\text{ m}\) west in \(15\text{ s}\). State the velocity for this second part.
c) Calculate the magnitude of the skateboarder's resultant displacement from the start.
d) Calculate the average velocity of the skateboarder for the entire \(40\text{ s}\) journey.