Physics: Speed and Velocity

Which of the following is a vector quantity?

• Speed

• Distance

• Velocity

• Time

Answer explanation

Velocity is a vector quantity because it has both magnitude and direction, unlike speed and distance, which are scalar quantities. Time is also a scalar and does not have direction.

Tags

NGSS.HS-PS2-4

NGSS.HS-PS3-5

Which graph represents a constant speed?

• Distance vs. Time

• Position vs. Time

• Speed vs. Time

• Velocity vs. Time

Answer explanation

The graph of Distance vs. Time shows a straight line, indicating a constant speed. In contrast, the other graphs represent varying speeds or velocities, which do not indicate constant motion.

Fill in the blank: The magnitude of displacement is known as _______.

• Distance

• Speed

• Velocity

• Time

Answer explanation

The magnitude of displacement refers to the shortest path between two points, which is defined as distance. Unlike speed and velocity, which involve time and direction, distance solely measures how far an object has moved.

Which of the following is used to describe a moving object with relation to a frame of reference?

• Speed

• Displacement

• Position

• Time

Answer explanation

Position describes the location of a moving object relative to a frame of reference. It indicates where the object is at a specific time, making it the correct choice over speed, displacement, or time.

Tags

NGSS.MS-PS3-1

Fill in the blank: The average speed is calculated by dividing total distance by total _______.

• Speed

• Time

• Displacement

• Velocity

Answer explanation

The average speed is determined by dividing the total distance traveled by the total time taken. Therefore, the correct answer is 'Time', as it is essential for calculating speed.

Fill in the blank: A scalar quantity has only _______.

• Magnitude

• Direction

• Velocity

• Speed

Answer explanation

A scalar quantity is defined by having only magnitude, which represents its size or amount. Unlike vector quantities, scalars do not have a direction. Therefore, the correct answer is 'Magnitude'.

Fill in the blank: The change in velocity over time is known as _______.

• Speed

• Acceleration

• Displacement

• Distance

Answer explanation

The change in velocity over time is defined as acceleration. It measures how quickly an object's speed or direction changes, making 'acceleration' the correct choice compared to speed, displacement, or distance.

What is the SI unit of distance?

• Meter

• Foot

• Kilometer

• Mile

Answer explanation

The SI unit of distance is the meter, which is the standard unit used in the International System of Units. Other options like foot, kilometer, and mile are not SI units.

Fill in the blank: The direction of motion is described by _______.

• Speed

• Velocity

• Displacement

• Position

Answer explanation

The direction of motion is described by velocity, which includes both speed and direction. Unlike speed, which is scalar, velocity is a vector quantity that specifies the direction of movement.

Motion is considered relative because:

• it depends on the observer's frame of reference.

• it is an absolute concept.

• it does not change with time.

• it is independent of external factors.

Answer explanation

Motion is considered relative because it depends on the observer's frame of reference. Different observers may perceive motion differently based on their own position and speed.