To determine the SI unit of speed, we need to recall the definition of speed and the SI units for distance and time.
\[ \text{Speed} = \frac{\text{Distance}}{\text{Time}} \]
\[ \text{SI Unit of Speed} = \frac{\text{SI Unit of Distance}}{\text{SI Unit of Time}} = \frac{\text{meter}}{\text{second}} = \text{meter per second} \]
This is commonly written as \(\text{m/s}\) or \(\text{m} \cdot \text{s}^{-1}\).
Correct Option: B) Meter per second
To identify the vector quantity among the given options, we need to understand the definitions of scalar and vector quantities. A scalar quantity is defined by its magnitude only, while a vector quantity is defined by both its magnitude and direction.
D) Velocity is a vector quantity because it possesses both magnitude (speed) and direction.
The question asks for the formula for average speed. Speed is a fundamental concept in physics and everyday life, representing how fast an object is moving. It is defined as the total distance covered by an object in a given amount of time.
This formula is universally accepted in physics and mathematics for calculating average speed.
A) Speed = Distance/time — This is the correct definition and formula for average speed. It states that speed is directly proportional to the distance traveled and inversely proportional to the time taken.
What is the acceleration of an object if its velocity changes from 20 m/s to 50 m/s in 5 seconds?
To find the acceleration of an object, we use the definition of acceleration, which is the rate of change of velocity. This means we calculate the change in velocity and divide it by the time taken for that change to occur.
Acceleration (\(a\)) is given by the formula:
\[ a = \frac{\text{Change in velocity}}{\text{Time taken}} = \frac{v - u}{t} \]Correct Option: B) The acceleration of the object is 6 m/s2.
The question asks about the type of motion exhibited by a freely falling object near the Earth's surface. We need to consider the forces acting on such an object and how they affect its velocity.
D) Accelerated motion. A freely falling object experiences a constant acceleration due to gravity, meaning its velocity continuously changes (increases in magnitude). Therefore, its motion is accelerated.
To answer this question, we need to understand the fundamental definitions of scalar and vector quantities, and how they apply to speed and velocity. A scalar quantity has only magnitude, while a vector quantity has both magnitude and direction.
Correct Option: B) Velocity is a vector quantity, while speed is a scalar quantity
This statement accurately reflects the definitions of velocity and speed in physics. Velocity includes both magnitude and direction, making it a vector, whereas speed only describes the magnitude of motion, making it a scalar.