Physics: Average Speed and Velocity

Questions and Answers

What is the unit of speed in the SI system?

kilometre per minute (km min–1)

metre per second (m s–1) (correct)

kilometre per hour (km h–1)

centimetre per minute (cm min–1)

What is the average speed of an object calculated as?

Total time taken - Total distance travelled

Total time taken / Total distance travelled

Total distance travelled / Total time taken (correct)

Total distance travelled * Total time taken

What is the term used to describe the rate of motion of an object with direction?

Motion

Speed

Acceleration

Velocity (correct)

What type of motion is described when an object moves along a straight line at a variable speed?

Non-uniform motion Signup and view all the answers

Which of the following is an example of non-uniform motion?

A bicycle moving at a variable speed Signup and view all the answers

What does the odometer of an automobile measure?

Total distance covered Signup and view all the answers

What is the shape of the path of an object in uniform motion?

Straight line Signup and view all the answers

If the average speed of an object is 3 m/s and the average velocity is 0 m/s, what can be said about its motion?

It is moving in a circular path Signup and view all the answers

How can the distance of a spaceship from a ground station be calculated if the time taken by a signal to reach the station is known?

By multiplying the speed of the signal by the time taken Signup and view all the answers

What is the average speed of a car if it travels 400 km in 8 hours?

50 km/h or 13.89 m/s Signup and view all the answers

Study Notes

Average Speed

Average speed is calculated by dividing total distance traveled by total time taken.
Formula: average speed = Total distance traveled / Total time taken
Example: A car travels 100 km in 2 hours, its average speed is 50 km/h.

Average Velocity

Average velocity is the arithmetic mean of initial and final velocity for a given period of time.
Formula: average velocity = (initial velocity + final velocity) / 2
Example: An object travels 16 m in 4 s and then another 16 m in 2 s, its average speed can be calculated.

Speed and Velocity

Speed and velocity have the same units (m/s or m s-1).
Speed only has magnitude, while velocity has both magnitude and direction.
Velocity can be uniform or variable, and can be changed by changing speed, direction of motion, or both.

Acceleration

Acceleration is the change in velocity of an object per unit time.
Formula: acceleration = (change in velocity) / time taken
Acceleration is a measure of the rate of change of velocity.

Accelerated Motion

Accelerated motion is a type of motion where velocity changes.
Example: A bicycle's velocity changes from 0 to 6 m/s in 30 s, and then changes from 6 m/s to 4 m/s in 5 s.

Units of Speed

SI unit of speed is m/s or m s-1.
Other units of speed include cm/s and km/h.

Displacement and Distance

Displacement is the distance measured from the initial to the final position of an object.
The magnitude of displacement can be equal to the distance travelled by an object, but not always.

Odometer and Distance Travelled

An odometer is a device that shows the distance travelled by a vehicle.
The difference between the final and initial readings of an odometer gives the distance travelled.

Speed and Velocity

Speed is the rate at which an object moves, measured by the distance travelled by the object in unit time.
The SI unit of speed is metre per second (m s–1).
Speed can be uniform or variable.
Velocity is the speed of an object moving in a definite direction, specifying both speed and direction.
Velocity can be uniform or variable.